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Das ^r^

Pflanzenreich

Regni vegetabilis conspectus

Im Auftrage der Königl. preuss. Akademie der Wissenschaften

herausgegeben von

A. Engler

Reihe Sarraceniales

(Engler, Syllabus [1892] 114)

Fam. ho. Sarraceniaceae

von

J. M. Macfarlane

(Heft 34; ausgegeben am 8. Mai igo8)

Fam. in. Nepenthaceae

von

J. M. Macfarlane

(Heft 36; ausgegeben am 20. Okt. 1908)

Fam. 112. Droseraceae

von

L. Diels

(Heft 26; ausgegeben am 31. Juli 1906)

Leipzig

Verlag von Wilhelm Engelmann

1908

•fr

QK

Pq-G ... 1-kFf- 3G»

Das

Pflanzenreich

Regni vegetabilis conspectus

Im Auftrage der Königin preuss. Akademie der Wissenschaften

herausgegeben von

A. Engler

IV. in

Nepenthaceae

mit 95 Einzelbildern in 19 Figuren

von

J. M. Macfarlane

Ausgegeben am 20. Oktober 1908

Leipzig

Verlag von Wilhelm Engelmann

1908

s

Nepenthaceae

von

J. M. Macfarlane.

(Gedruckt im März bis Juli 1908.)

(Cytinearam pars Brongn. in Ann. sc. nat. I. (4 82 4) 42. — Nepentheae Blume, Enum. pl. Javae I. (1827) 84. — Aristolochiacearum pars R. Br. in Trans. Linn. Soc. XIII. (1822) 219. — Aristolochiarum sect. Nepenthinae Link, Handb. I. (1829) 369. — Nepentheae Lindl. Nat. Syst. (1830) 154. — Nepenthaceae Lindl. Nat. Syst. ed. 2. (1836) 204. — Scrpentariae sect. Endl. Gen. (1836 — 40) 345. — Nepenthaceae Benth. et Hook. f. Gen. III. (4880) 115.)

Wichtigste Litteratur. Systematik: Linnaeus, Spec. pl. (1753) 955. — Jussieu, Gen. ( 1 78 9) 444. — Loureiro, Fl. cochinch. (sub nom. Phyllamphora)

II. (1790) 606. — Poiret in Lam. Encycl. IV. (1797) 459. — Willdenow, Spec. pl. IV. (1805) 874. — Aiton, Hort. Kew. ed. 2. V. (1813) 420. — Brongniart in Ann. sc. nat. I. (1824) 29. — Nees von Esenbeck in Ann. sc. nat. III. (1824) 365. — Loddiges, Bot. Cab. XI. (1825) t. 1017. — Sims, Graham, Hooker f. in Bot. Magaz. LIII. (1826) t. 2629, LV. (1828) t. 2798, LXXIII. (1847) t. 4285, LXXXIV. (1858) t. 5080, LXXXV. (1859) t. 5109, CXVI. (1890) t. 7138. — Blume, Enum. pl. Javae I. (1827) 84. — Jack in Comp. Bot. Magaz. I. (1835) 269. — Blanco, Fl. Filipp. ed. 1. (1837) 805, ed. 2. (1845) 555, ed. 3. III. (1879) 214. — Korthals, Verhand. Bot. (1839) 1. — Griffith, Itin. II. (1848) 76, Notulae IV. (1854) 348. — Blume, Mus. Bot. Lugd. Bat. II. (1852) 1. — Miquel, PI. Jungh. I. (1851) 168, Fl. Ind. bat. I. (1855) 1069, in Journ. Bot. Neerl. I. (1861) 272, 111. Fl. Arch. Ind. (1871) 1. — Hooker f. in Trans. Linn. Soc. XXII. (1859) 415. — Oudemans, De Bekerplanten (1863) 1. — Wunschmann, Gattung Nep. (lnaug.- Diss. 1872) 1; in Engler-Prantl, Pflzfam. III. 2. (1891) 253. — Hooker f. in DC. Prodr. XVII. (1873) 90. — Masters in Gard. Chron. (1881) II. 524, (1884) I. 576, (1887) II. 681, (1889) II. 492, (1890) IL 48, 240, 501. — Beccari, Malesia III. (1886) 1. — Hooker f. FI. Brit. Ind. V. (1890) 6J3. — Warburg in Engler's Bot. Jahrb. XIII. (1891) 318. — Macfarlane in Ann. of Bot. VII. (1893) 440. — G. Beck in Wien. 111. Gart. Zeitg. XX. (1895) 96. — Hemsley in Kew Bull. (1895) 116; in Gard. Chron. I. (1905) 241, 2 60; in Garden LXVII. (1905) 250; in Hook. Ic. pl. XXIX. (1906) t. 2814. — Bailey in Queensl. Agric. Journ. I. (1897) 369, III. (1898) 354, VII. (1900) 441. — Rudolph in Journ. Soc. Nat. d'Hort. Fr. (1896). — Dubard in Bull. Mus. d'Hist. Nat. XII. (1906) 62.

Morphologie, Physiologie und Entwicklungsgeschichte. Gaertner, De Fruct. II. (1791) 18. — De Candolle, Organ. Veg. I. (1827) 279, 320. — R. Brown in Lond. Eclinb. Phil. Mag. I. (1832) 3 16 et in Mise. Works II. (1867) 358. — Korthals, vide supra. — Griffith, Notulae I. (1847) 232. — Don in Proc. Linn. Soc. I. (1849) 91. — Voelcker in Ann. Mag. Nat. Hist. ser. 2. IV. (1849) 128. — Hooker f. in Trans. Linn. Soc. XXII. (1859) 137; in Report. Brit. Assoc. (1874)

III. — Oudemans, De Bekerpl. (1863) 1. — Morren in Bull. Acad. Brux. V.

A. Engler, Das Pflanzenreich. IV. (Embryopuyta siphonogama) 111. \

2 J. M. Macfarlane. — Nepenthaceae.

(1838) 430, 582. — C. Morren in Belg. Hort. IL (1852) 227. — Hildebrand in Bot. Zeitg. XXVIII. (18~0) 593. — Wunschmann' vide supra. — Gorup-Besanez et Will in Phys. med. Soc. Erlangen VIII. (1876) 152. — Vines in Journ. Linn. Soc. XV. (1877) 427. — Zacharias, Anat. Stam. Nep. (Inaug.-Diss. 1877) 4. — Burbidge^ Gard. of Sun (1880) 40 — 344; in Gard. Chron. ser. 2. X. (1880) 201, XVII. (1882) 56. — Dickson in Journ. of Bot. XIX. (1884) 133; in Gard. Chron. XX. (1883) 812. — Bower in Ann. of Bot. III. (1889) 239, IV. (1890) 165. — Macfarlane in Ann. of Bot. III. (1889) 254, VII. (1893) 420. — Goebel, Pfl. Schild. II. Lief. 1.(1891) 93, Lief. 2. (4893) 186. — Bokorny in Pringsh. Jahrb. XX. (1889) 445. — Dubois in Compt. Rend. CXI. (1890) 315. — Tischutkin in Bot. Centralbl. L. (1892) 304. — Massart in Bull. Soc. Roy. Bot. Belg. XXXIV. (1895) 253. — Veitch et Burbidge in Journ. Roy. Hort. Soc. XXI. (1897) 2 26, 262. — Vines in Ann. of Bot. XL (1897) 563, XII. (1898) 545, XV. (1901) 563. — Buscalioni et Fermi in Ann. R. Ist. Roma VII. (1898) 99. — Clautriau in Mem. Acad. Roy. Belg. LIX. (1900) 1. — Fenner in Flora XCIIL (1904) 358. — Heinricher in Ann. Jard. Bot. Buitenzorg ser. 2. V. (1906) 277.

Character. Flor es dioeci, apetali, inconspicui, virides aut purpurei, entomophili, saepe odore foetido. Sepala 4, rarius 3, distincta v. rarissime basi connata, hypogyna, imbricala, sed in paria duo aequalia v. rarissime inaequalia disposita, extus ± pubescentia, intus glandulosa et nectarifera. Stamina 24 — 4, filamenta in columnam connata, antherae in capitulum congestae, uniseriatae v. subbiseriatae v. biseriatae, parallelae v. tz: convolutae, biloculares, extrorsae, longitudinaliter dehiscentes; pollen trilobatum. Carpella 4, rarissime 3, sepalis opposita; ovarium sessile v. breviter stipitatum, ova- tum v. oblongum, cylindricum v. tetragonum, dz pilosum, intus 4 — 3-loculare; Stylus 0 v. rarius brevis, crassus, stigma discoideum planum v. medio depressum, 4- rarissime 3-lobatum, lobis solidis v. ± lobatis; ovula oo anatropa, angusta et elongata, multi- seriata, ascendentia, placentis centralibus affixa. Fructus capsularis, sessilis v. bre- viter stipitatus, fusiformis usque ovatus, coriaceus, 4- rarius 3-gonus, fusco-nitidus, loculicide dehiscens; valvae lanceolatae v. ovatae medio septiferae, apice lobis stigma- ticis planis v. depressis, simplicibus v. bilobatis coronatae. Semina oo imbricata ascendentia filiformia, funiculo tenui placentis affixa; testa membranacea bicaudata breviter v. longe elongata, circum embryonem ± relaxata et sinuosa, raphe filiformi ascendentia; albumen carnosum, embryo cyündraceus rectus in axi albuminis; cotyle- dones lineares in germinatione demum virides et epigaeae, radicula brevis infera.

Suffrutjices fruticesve, prostrati erecti v. scandentes, ad 0,5 — 15 m alti. Caulis cylindricus usque trigonus, nudus vel prolongationibus ab basibus foliorum de- currentibus alatus, glaber v. ± hirsutus. simplex v. ramosus. Folia alternantia, raris- sime ad V2 plerumque ad 2/s spiraliter disposita, integra, exstipulata, sessilia v. peliolata, membranacea, herbacea v. saepe coriacea; folia adulta in petiolum, laminam, cirrhum, ascidium et operculum divisa; petiolus ubi formatus dz elongatus alatus, basi saepe amplexicaulis; lamina alabastro involuta pubescens rarius glabra, demum lanceolata ovalis v. obovata, nervis longitudinalibus 2 — 15 parallelis, e costa v. e basi folii egre- dientibus, nervis transversis parallelis v. irregulariter areolatis, versus costam transversis v. oblique ascendentibus; cirrhus ab costa valida laminae prolongatus, tenax, saepissime convolutus et scandens, apice in basim ascidii ampliatus; ascidia monomorphia dimorphia v. trimorphia, inferiora saepe ampullacea usque ventricosa alis ventralibus dz expansis et ciliatis, ascidia superiora vel solum evoluta cylindracea alis reductis, summa infun- dibuliformia alis saepe ad nervös prominentes reductis, os transversum v. obliquum, saepe in collum postice productum, margine dz transverse expansa, coriacea, nitida striata et in peristomium formata, ascidium inlus per totum nitidum glandulosum et »detinens« (p. 20) v. parte superiore eglandulosum glaucum opacum et »deducens« (p. 20); operculum ovatum ellipticum v. orbiculare, primum os claudons demum ex- pansum et inclinatum erectum v. reflexum, postice versus os ascidii articulatum, intus

J. M. Macfarlane. — .Xepcnthaceae. 3

sparse v. copiose glandulosum et nectariferum ; costa folii parte posteriore oris ascidii et insertione operculi in calcar simplex, v. rarius 3 — 5-fidum, producta. Inflorescentia terminalis et folio opposita, cymosa, paniculata, cymis densis composita vel ad racemum simplicem reducta, pedicelli tenues, bracteolati vel ebracteolati.

Vegetative Organs (Vegetationsorgane). Germination of the seeds of Nepenthes takes place readily and abundantly within 5 to 6 weeks after they are ripe, if kept in moist surroundings such as the surface of Sphagnum or amid loose humus. They also require a temperature of 25° to 30° C. The seed-coat ruptures along one side from elongation of radicle and hypocotyl, and from curvature of the latter and of the cotyledons into a saddle that gradually straightens tili the linear green cotyledons are set free from the seed cavity. The radicle of the seedling steadily lengthens during the first year tili it may be iO — 15 cm long. Lateral rootlets are formed acropetally on it, and in considerable number. These incline to grow obliquely downward or even horizontally , since thorough aeration is essential to their welfare. The entire root system of the plant is therefore formed near the surface of the soil, and is most per- fectly developed when amid loose decomposing vegetable humus, decaying fibrous roots of other plants or open gravelly soil that is permeated by decaying vegetable material, as indicated by Korthals, Burbidge and Scott-Elliot, and as praetised in successful greenhouse cultivation.

The annual growths of fine fibrous roots, in about i 5 species studied, are greenish- yellow round the growing apex, but soon they assume a black-brown color. They are closely beset with brown absorptive root hairs, all of which remain functional throughout the season. Subsequent annual development results in the production of a copiously branched root system. Some authors have stated that average root-develop- ment in Nepenthes is comparatively poor and feeble. In healthy well grown plants this is not so. The active absorptive root-hair system is also exceptionally rieh and abundant. By subsequent formation of a root cambium and associated tissue, the brown epidermal layer and subjacent cortex become split and ultimately shed in older roots. These then assume a yellow or flesh color that may be retained for years, but finally they become yellow-brown.

The young stem is at first closely beset by leaves placed in rosette fashion (Fig. \ C), since its internodes are almost suppressed. With increasing age the internodes gradually lengthen in most species. But in N. ventricosa, N Northiana and others the internodes remain short, and so the adult leaves are inserted in close proximity to each other. If N. Smilesii and N Älicae are mature species — and all present evidence is in favor of this — their stem attains a length only o£ 20 — 30 cm and is upright. In N Veitchii, from the seedling stage onward, the stem as originally des- cribed by Burbidge is prostrate, and creeps epiphytically along the branches of trees. It then forms its leaves in close succession and in two-ranked order, but it seldom attains a greater length than 1 — 1,5 m in the living part, while the posterior portion tends to die away. This habit is perfectly retained under cultivation, and when plants are grown in a soil of fibre and sphagnum roots may grow down from the crowded nodes. In N. ampullaria, N melamphora etc.. the main stem may elongate, and by aid of the leaf-tendrils may climb to a height of 2 — 6 m. But in these and other species if the main stem or lateral branches fail to reach a support, they may lie along the ground, root abundantly at the nodes, and there produce on short lateral branches dense Clusters of leaves with reduced lamina but large and often richly colored pitchers (Fig. 13 p. 32). The largest and heaviest stems of the group are those of X. Raffks-iana, N Burbidgei, N. Boschiana and N bicalearata which attain a height of 6 — 2 0 m, while the last may be 3 cm across. In color the stem and branches are green during the first few months of growth as a rule. In such species as N. albo-marginata and N anamensis they may vary from green to dark claret. With age all become brown and somewhat brittle in consistence. They are usually

4

J. M. Macfarlane. — Nepenthaceae.

cylindrical, but may be sharply Irigonous as in N. tentaculata and N. Bongso, or 3 — 4- gonous as in N. gracilis, where the wings from one leaf above may be prolonged downward along the angles of the axis for 5 — 8 cm to meet the next leaf below. The young stem and branches are often clothed with a dense pubescence of a ferru- ginous or more rarely of a pale hue. This usually is shed within a few weeks, though it may persist for a much longer period as in N. hirsuta. Many of the species develop

alluring honey glands (p. \ 4) on the young annual shoots. These glands appear as small papillae in the centre of a circular or elliptic area, and may be of a crimson hue. They are never abundant, are usually scattered, but may be prominent in N bicalcarata etc.

As in the Sarraceniaceae , so in the Nepenthaceae, the cotyledo- nary leaves are green, and are re- tained within the albumen of the seed tili this is absorbed. The coty- ledons in both families closely re- semble each other, but those of the Nepenthaceae are typically elliptic (Fig. \A). As in the Sarraceniaceae they are succeeded by pitchered seedling leaves, of which 8 — 10 that resemble each other may be formed as a little rosette on the ground. Each becomes increasingly longer than its predecessor (Fig. \ J9, C) and, as emphasized by Hooker andDickson, they suggest decided affinity with leaves of Sarracenia. They are still more nearly related to those of Heliamphora. Each of the 6 to 8 leaves first produced consists of a sheathing petiolar rib that is gradually prolonged upward into a broad laminar midrib whose upper extremity is hollowed out from above downward. The petiolar rib bears lateral wings that broaden out and are continued upward as lami- nar expansions of the midrib. The front or ventral part of the laminar midrib is somewhat flat and bears the laminar expansions on either side, so that the pitcher appears as a hollow appendage to the under sur- face (Fig. { C, D). As development proves, the pitcher is an inpouching from the upper surface of the leaf near its apex. But by transverse growth in front of and below the pitcher oriflce the laminar expansions may form a peltate union, as described by Hooker and by Dickson, and as observed by the writer in three sets of hybrids. Goebel however failed to notice such a peltation in specimens studied by him.

Fig. \. Seedlings of Nepenthes. A Cotyledonary stage. B Seedling with first piteher-leaves. C Later stage. D Early seedling leaf. JE Tenth leaf from cotyledons. F Transition leaf between early seedling and adult leaf; a petiole, b lamina, c pitcher with wings. d lid or operculum. (Icon. orig.)

J. M. Macfarlane. — Nepenthaceae. 5

The mouth of the seedling pitcher is bounded by a narrow corrugated rim, that is foraied by outward and inward growth and reflection of the margin. The cellular and specially the vascular tissue of the pitcher is prolonged round and behind the mouth to end in a pointed process or spur on the dorsal side. This is the organic apex of the leaf. Between the apex and the orifice the lid grows out to overhang the latter. The margins of this lid like the margins of the lamina, are often glandular-ciliate. In the 8th to 1 0lh seedling leaf the pitcher is hollowed out of the midrib of the distal laminar half only, and is being gradually constricted off round its base from the inferior or proximal laminar half (Fig. \ E — F), which remains continuous with the winged petiole. The laminar wings of the distal pitchered portion thus become the ventral wings of the pitcher. These become wide and highly conspicuous objects in JV. ampullaria (Fig. 1 3, p. 32), JV. Rafflesiana (basal pitchers), JV. bicalcarata and others. They are often richly provided with alluring glands. In succeeding leaves the distal or pitchered part becomes completely separated from the proximal part, that has usually been called the lamina or blade, through increasing elongation of the midrib between the two (Fig. \ E) and conversion of it into a functional tendril. It will thus be seen that the funda- mental morphological similarity of the Nepenthes and Heliamphora (q. v.) leaves is perfect, and that the rather puzzling adult leaf of Nepenthes is readily interpreted when its morphological evolution from the earliest seedling stage is traced.

The adult leaf in petiolate species like JV. phyllamphora, JV. Rafflesiana etc. consists of [a] a petiole that is usually winged. The wings may be horizontal, or directed obliquely or vertically upwards as in JV. rajah and JV. maxima. Frequently the expanded base of the petiole and of its wings enlarge into an amplexicaul attach- ment to the stem, while in such species as N. gracüis (Fig. 2) and JV. Burbidgei the wings may be prolonged down the stem almost to the insertion of the next lower leaf. That portion which we will subsequently speak of as (b) the lamina or blade is clearly proved, by the above history of seedling leaves, as well as by leaf-embryo- logy, to be but the basal part of the entire lamina. In view however of its relatively extensive green surface, we will for convenience speak of it as the lamina. The pro- longed petiolar midrib that is continued upward as the laminar midrib may be strongly concave on its upper and still more strongly convex on its under surface. The lamina varies from semimembranous to succulent-leathery or leathery in consistence, from linear-lanceolate to oval or elliptic in outline, and from bright green to dark green or reddish green in color. Rarely as in JV. madagascariensis the lower surface may be greenish-crimson to crimson. In most species the laminar halves end abruptly or by tapered extremities in the prolonged midrib or tendril. But in such as JV. rajah, JV. Northiana and at times JV. maxima the halves of the lamina become peltately fused above the excurrent tendril. The margin of the lamina is usually entire, but in the group of related species that includes JV. phyllamphora and JV. Bernaysii the margin is ciliate-toothed.

Valuable characters for distinguishing the species are furnished by the venation. In all of the species two or more veins run parallel to and on either side of the midrib, but at varying distances from it and from each other. These usually start from the midrib, near its junction with the petiole, but sometimes they pass directly from the base of the petiole upward along its wings, and then spread into the lamina. In a few species such as JV. alata, JV. madagascariensis and JV. Reinwardtiana each leaf has sevcral pairs of veins, but the innermost two to four pairs spring at d afferent levels from the rib, the innermost pair starting at or above the middle of the leaf, while those further out start from the midrib at varying levels below. In striking contrast to the foliage leaves are the bracts, which are typically sessile, and whose venation nearly always differs fundamentally from that of the foliage leaves, even on the same plant (Fig. \ 5). In these the longitudinal veins are undeveloped or appear only as one or two faint marginal lines, while the substance of the bract is traversed by an abundant reticulation of oblique or nearly transverse veins. The greatest

{} J. M. Macfarlane. — Nepenthaceae.

development of longitudinal veins occurs in N. bicalcarata, where 12 to 15 may run on either side of the midrib. The parallel veins are united by numerous transverse ones, that may radiate out at right angles to the rib, or may run more or less obliquely upwards. All of these may be of equal strength and continuity, but more frequently each alternate vein is finer and shorter than that above or below. The branching and reunion of the veins are copious and intimate, so that the leaves are extremely resistant to strains. The vernation of the leaves is involute.

The next leaf portion, the (c) tendril or cirrhus is, as already described entirely absent froni the earliest or seedling leaves, and only begins to form as the pitchered part of the lamina grows asunder from the basal part. In adult leaves it is nearly

Fig. 2. Nepenthes gracilis Korth.

J. M. Macfarlane. — Nepenthaceae. 7

always well developed and of great tensile strength. Thus the tendril of N. Raffle- siana may be loaded with a weight of six kilos without rupture. Like other tendrils they are sensitive to contact Stimulus when young, and may then coil round supports by two or three spirals, after which it is difficult to displace them. Only in short upright or in creeping species such as N. rajah and N. Veitchii do the tendrils remain straight and uncoiled. They are rarely uniform in thickness, usually they enlarge suddenly or gradually as they near the pitcher base. An interesting biological condi- tion of the tendril is seen in N. bicalcarata, the structural relation of which was first explained by Beccari and Burbidge. Like the tendrils of most Nepenthes this has alluring honey glands, but here they are exceptionally large and numerous, appearing as evident papillae over the surface. Opposite the middle or lower half of the pitcher, where these glands are most numerous, a swelling that is about twice the thickness of the tendril above or below, is seen in wild specimens, and a similar though more reduced swelling is seen in cultivated specimens (Fig. i 4). The swollen area is hollow- ed out and occupied as a formicary by ants. About the middle of the area is a circular hole, the entrance of the formicary (Fig. 1 4). The hole seems, at least in some cases, to have been the duct of a honey gland that the ants have gnawed into and enlarged while sipping its nectar. The liquid contents of the pitcher cavity, filtering upward through the cells of the tendril, can be sipped by the insects in safety. This constant liquid supply has caused enlargment and watery hypertrophy of the area. Its central cells break down or are destroyed by the ants, and the cavity thus formed becomes a formicary. As Beccari has shown it may vary in size from 2 — 6 cm X I cm. From the standpoint of plant heredity it is significant to note that the swelling always persists in cultivated plants, though these are not frequented by, nor perforated by, appropriate ants.

The next area of leaf specialization is [d) the pitcher or ascidium. The con- stituent parts of this have been very variously interpreted by different botanists. Their views are in part set forth by Bower and the writer [Ann. of Bot. III. (1839) 239, 254; IV. (1890) 165; VII. (189 3) 450]. The adult pitchers in some species are all uniform or monomorphic, in other species dimorphic types of pitcher are produced, while several are trimorphic in that three distinct forms of pitcher develop at different heights on the plant. Alike from evolutionary, embryological and morphological evi- dence, the primitive type seems to be the tubulär pitcher, that approximates in shape to pitchers of some species of Sarraceniaceae. This shape is retained in most of the monomorphic species such as N. gracilis (Fig. 2), N. khasiana, and N. phyllamphora. But possibly through weight of the liquid contents of the lower or terrestrial pitchers while these rested on the ground, some species bear ampulliform or goblet-shaped pitchers below, while the upper suspended or cauline ones are tubulär or tubulär ventricose (Fig. 1 5). N. alata, N. ampullaria, N. anamensis, N. melamphora and others show such dimorphic conditions. But in N. Boschiana, N. maxima, N. Vieil- lardii and less strikingly in a few other species, the lowest pitchers are ampulli- form, those above are tubulär, while toward the upper part infundibuliform or cornu- copioid pitchers are alone produced. Gradation types between all of these are usually noted.

As study of the seedling pitcher in relation to the adult pitcher shows (Fig. 3A — Z)j, the often wide and almost flat area that intervenes between the wings of the pitcher on the ventral surface, ' is the expanded upper or ventral side of the midrib. The remainder of the pitcher wall is the inflated lower or dorsal side of the midrib. As is proved by successive stages in the evolution of seedling leaves, the pitcher wings represent the upper lobes of the originally continuous lamina, that become completely separated from the inferior or basal halves, by intercalary growth of the midrib region that becomes the tendril. These wings are usually well developed as lateral often ciliated expansions that traverse the length of the pitcher in the terrestrial type of the dimorphic species cited above. Their often richly ciliated margins are in striking contrast

s

J. M. Macfarlane. — Nepenthaceae.

to the straight margins of the narrow or ridge-like wings seen usually in the tubulär or funnel-shaped upper pitchers.

The color of the pitcher surface, including the wings, varies greatly in different species, and may even vary much in different pitchers of the same individual, according to age, exposure lo light, and soil conditions. In N. ampullaria, N. Veitchii, N. distillatoria the pitcher is often uniformly green ; in N. gracilis, N. khasiana and N. hirsuta it is green and finely spotted or even suffused with red or crimson; in N. maxima, N. Northiana and N. Rafflesiana it is light green with sharply defined and often extensive spots or blotches of a deep crimson hue; while in N. sanguinea, N. Edwardsiana and N. villosa it is largely or wholly of a rieh scarlet or crimson color. N. Rafflesiana var. nivea and N. Burbidgei bear pitchers that are typically of a porcellanous white color with deep crimson blotches. Some species may be dimorphic

in color as well as shape. Thus the relatively large lower or soil pitchers of N. ampullaria are often in the wild state richly blotched with crim- son, while the aerial and smaller pit- chers may be almost or wholly green. Similar Variation is seen in N. alata, N. Macfarlanei, N. rajah. Green and red varieties of the same species are not unfrequent, as in N. bicalcarata, N. distillatoria, and to a certain degree N. Rafflesiana. Several tra- vellers have commented on the fact that the basal, more shaded and even moss-covered pitchers of such species as N. rajah and N. Edwardsiana are much more highly colored than are the sun-exposed cauline pitchers, though the exaet explanation of this does not yet seem to have been given.

The fundamental color of the pitcher may be somewhat modified in appearance by local or general hair coverings. Thus the green pitchers of N. anipullaria and N. hirsuta, also the crimson-green pitchers of N. villosa may be brownish-green or brownish-crimson in the young state, owing to the abundance of long ferru- ginous hairs. In N. albo-marginata and to a less degree in its probable hybrid N. cirieta, a white belt of long stellate hairs in the former, and of brownish- white hairs in the latter, Surround the pitcher margin beneath the peristome.

The distribution of veins throughout the pitcher wall is in all cases copious. The circle of vascular bundles that enters the base of the pitcher from the tendril, spreads out into two Systems. One of these, pursuing a ventral or upper course, consists of two main lateral veins that run upward along the edges of the widened-out ventral part of the pitcher. From these veins pass outward into the ventral laminar lobes or wings when such are well developed, and inward across the ventral area between the wings to unite with one or more median veins that run up the front of the pitcher. The second and more abundant system is composed of numerous veins that curve

Fig. $, Development of Nepenthes leaf. A Foliar rudiment showing commencing depression for pitcher cavity. B More advanced stage. G Terminal part of leaf. D Leaf cut above petiole; a petiolar base, be laminar rudiment continuous with pitcher wings, d pitcher depression and lid, e leaf apex, with lateral lobes in 4. (After Hookcrf.)

J. M. Macfarlane. — Nepenthaceae.

outward and run upward along the lateral and dorsal sides of the pitcher, tili they approach the pitcher oriflce. The lateral veins, as well as the upper ends of the ventral ones then curve gracefully round toward the dorsal region, and in their course give off minor bundles that run up into the substance of the thick corrugated peristome. Here each bündle divides along the inner margin into still smaller bundles that Sur- round the marginal glands of the rim. The recurved lateral and the dorsal veins converge and thin out toward the point of insertion of the lid, into which they give off two main veins. Their now attenuated extremities end in the dorsal spur, situated behind and near the point of insertion of the lid. This spur has therefore generally and rightly been regarded as the organic apex of the entire leaf System.

A noteworthy relation of the veins of the pitcher is that every gland, whether external or internal in Posi- tion, has a bündle termination endin g in or around it. This can be beautifully demonstrated to the naked eye, by macerating a pitcher in hot potash Solution for 20 — 30 minutes, and then removing the outer and inner epi- dermis in water. The looser mesophyll tissue readily washes away, and the bündle twigs that supplied the glands appear as fine branch terminations of the vas- cular network of the pitcher.

The alluring glands of the leaf are readily visible to the naked eye, and are more or less developed from the base of the petiole to the peristome and the outer lid surface. Their microscopic structure is described later (p. \ 7). In such species as N. ampullaria and N. Ttaf- flesiana they are scarce over the petiole and lamina, but a few may be observed along the sides of the lower midrib surface, as minute papillär swellings that exude a sweet juice in fresh leaves. They are somewhat more abundant over the pitcher wings, less so over the dorsal part of the pitcher. In N. Veitchii, N. khasiana, and N. maxima they are frequent over the petiole and lower laminar surface. In N. Northiana and N. sanguinea they are also found on the upper laminar surface, the tendril and the pitcher. But in N. bicalearata they attain largest size and are quite abundant. Here they offen form con- spicuous warts along the sides of the petiole, the midrib Fig. 4. Nepenthes gracitis Kovlh. and the tendril. These glands , in conjunction with the Extremity of lamina with midrib alluring glands of the stem, tempt insects upward by prolonged into a tendril or cir- their secretion, to the pitcher mouth or to the lid. In rhus M? that exPands into a

hot dry weather the sweet secretion may even dry, so

pitcher shown in section; e oper-

, culum in section, d corrugated as to appear as a fine white vermiform thread attached peristome) c deep conducting

to the oriflce of the gland. surface; b detentive and digesUve

The peristome or corrugated rim of the pitcher surface with digestive glands.

(Fig. bd) is a conspicuous feature in nearly all species of (After Sachs.)

the genus. N. Lowii (Fig. \ 9) is the only species in which

it is undeveloped, the pitcher margin being straight and somewhat reflexed. Along its

inner margin are fine parallel longitudinal ridges, that indicate vascular bundles tra-

versing the internal tissue. Each ends below the edge in a deeply sunk marginal

gland that opens by a small papillär pore. The pores collectively form a dotted line

about 4 — 6 mm beneath the edge of the pitcher. The typical peristome is formed in

part from incurving of the margin, which up to the period of opening of the young

pitcher is a uniform rim that projects upward under the closely fitting lid. In part

10 J. M. Macfarlane. — Nepenthaceae.

also it results from growth and recurving of a circular area below the rim, that ap- pears as a circular swelling below and outside of the lid in the young pitcher. The zone of tissue just beneath the recurved portion often develops a copious feit of hairs that attain their maximum in N. albo-marginata, the rim of which is subtended by a white tomentose band. The convex surface of the mature rim is firm and shining, owing to heavy cutieularization of its epidermal cells. It is traversed by fine or pro- minent parallel ridges that are above and in line with vascular bundles. Its surface affords a very insecure foot-hold for insects. The ridges are usually prolonged beyond the infolded margin as teeth of varying length. While the ridges and teeth are very feebly developed in N. Reinivardtiana, they become long evident processes in N. mel- ampliora, N. villosa and N: Edwardsiana. But their most striking development is reached in N. eehinostoma, where the entire rim has become split up into a double row of incurved teeth that project toward the pitcher mouth. Round the infolded margin of the peristome, or toward the tips of the teeth are pores that correspond to those already mentioned in N. Loivii. These open into longer or shorter canals, that are in line with, and act as ducts for, the deeply embedded marginal glands. From these glands a sweet juice is discharged that is greatly relished by insects. In relation to the size of the pitcher, the widest and most perfectly inclined peristome is that of N. ampullaria (Fig. \ 3). Those of JV. Northiana, N. rajah, N. sanguinea and N. Veitchii form a wide conspicuous often richly colored "frill" round the mouth. But more commonly the peristome is a nearly uniform circular collar, as in N. gracilis, N. khasiana and N. phyllamphora. It attains huge proportions in N. villosa (Fig. 9) and JV. Edwardsiana (Fig. 16, p. 53) where it is a broad cylinder elevated at rather distant intervals into plate-like ridges that are continuous with the long marginal teeth. In several species, notably N. Hemsleyana and N. Rafflesiana the peristome and pitcher wall are greatly elevated posteriorly into a high neck that bears the lid. The upper halves of the peristome, in the latter species, are widened out, while the ridges and teeth are decurved toward the pitcher orifice. This becomes more pro- nounced in N. bicalcarata, where the uppermost parts of the peristome are lengthened out, decurved, and tapered into two hard sharp pointed spurs or spines that overhang the pitcher orifice (Fig. \ i). Burbidge's explanation of their significance seems good. He observed in North Borneo that the pitchers of many species are visited by the small rodent Tarsius spectrum. Perched on the pitcher margin, it bends in its head and neck, scoops out the caught insects and devours them. But if it attempts such action with N. bicalcarata the two sharp spines often transfix it by the nape of the neck, and tumble it into the pitcher, or frighten it from attempting such action on other pitchers of the species. Another suggested explanation of the spines has recently been made, by supposing that they exude honey drops by their tips from a few marginal glands that are so placed as to cause an insect that attempts to sip, to drop off into the pitcher cavity. Such may be a partial reason for their gradual evolutionary selec- tion and development, but Burbidge's view seems more natural.

The lid or operculum (Fig. 4e) is always developed, but it varies from a small narrow elliptic process as in N. ampullaria (Fig. 1 3) to large cordate or reniform expansions as in N. rajah and N. bicalcarata (Fig. 14). Bower and the writer have both suggested, from embryological (Fig. 3 c) and morphological evidence that the lid is to be viewed as two peltately fused laminar lobes or leaflets. Bower regards them as leaflets that are distinct in morphological value and continuity from the laminar lobes in front of the pitcher, and from the basal laminar halves. The writer views them as lobes of the primitively continuous lamina, that have early become rounded off and fused in peltate fasbion in front of the spur to form the lid, while later and less perfect Separation of the pitcher wings and the laminar lobes has occurred. Eacb lid shows, in most species, two strong and somewhat approximated veins running into it, and distributing minor median and lateral veins. Its apex is often emarginate or indented. Ils external surface closely agrees with that of the outer pitcher wall, alike

.1. M. Mact'arl

Nfiientliaceae.

1 1

in color. in hair-development, and in the [»resence oi' oceasional alluring glands. Ils internal surlace inav be entirelv devoid oi' nectar glands as in Ihe rudimentary lid of X. ampullaria, but in mosl species it is richly siuddcd witli glands whose sweel secretion is attractive to inse ts. In A. ulatu, X. Hasch i<t na, X. Hurhiibjat. X. VeitcJtii and X. maxitna Fig. 18 Ihe inner Imse ui' the liil is expanded into a ver- tical eres! (hat is copiously covered witli glands. wliile in A . muxiniu an ad<litiünal tongue-shaped or at times filiform outgrowth starts fruni near Ihe 1 i • 1 apex. Two species only, A. Loi'ii ,Fig. I 9 and A. Maifirlaiu i develop long attennate hairs l'roni Ihe inner lid surlace, Ihat are seattered amongsl the nectar glands. In A. tcu- tacidata Fig. |ü a l'ew siniilar hairs spring [Vom the onter lid surlace. ollen near the margin, but such are ahsenl in the var. inibcrbis, while the hairs mav he l'ew on the inner lid surlace ol' A'. Marfarlawi. In developing pilchers that have alinosl attained their lull size, the lid is applied verv closelv to a circular it oblique area. heneath the as yet uniform margin ol' the pitcher. and ahove a slightlv hulged pari ol' it. So tightly is the lid applied, and so closelv du the hairs ol' the zone interweave, Ihat Ihe pitcher is Ihoroughly air-tighl, and considerahle [iressure is needed in l'orce open Ihe lid. or to hurst the pitcher. At such a stage in developinent, one ran readily see 1>\ shaking the pilchers of most speeies, thal a considerahle (juantily ol' liquid lias already aecumulated at the bottoni oi' the pilcher-cavity. This lias cxuded IVom the inner pitcher wall, aml is neutral in chemical reaction.

The calcar or« spur is a shorl straighl or inore ollen curved [imcess, that pro- jeets from the posterior apical pari ol' the pitcher, hehind the insertion ol' Ihe lid. This has properly heen regarded as the organic apex ol' the leat", alike on emhrvological and niorphologieal grounds. Thus in Ihe enihryo pitcher Ihe spur is the terminal pointed apex, helow and in front of whicli the future lid originales as a usuallv hiloheil process, and the future pitcher cavity as a small depression In:. 3 />'. C. In the adult pitcher also Ihe vascular svstem converges toward the spur and in [iarl ends in it. II is usuallv a simple filiform attenuate process, hui in several Australian sjiecies it is flattened from ahove downwards. while in X. ampullai'in Fig. I :> . A. tnümii lata etc. it may bear several paired or unpaired lateral processes, Ihat Ihe wrilcr views as srreallv reduced leallets.

Anatomy (Anatomische Verhältnisse). Koot system. Transverse section of a

voung rool extremilv shows an epidermal laver wilh dark hrown cell walls. The free face of each cell is considerahly thicker t hau the lateral and inner faces. From Uns laver originale Ihe ahundant dark hrown rool hairs. 'Ihe cortex cnii>i>ls of Ihree rather irregulär kntrs of rounded cells wilh hrown slightlv thickened walls. These contain manv small single or ai.rLrre^alt^ or Compound starch grains. The endodermis is a Iayer of nearlv cuhical cells conlaining small stareh grains. The pericamhiuni is a single layer of cells, and from it originale man\ lateral rootlets, hui a considerahle Hinüber fail to develop. The vascular bündle system is slaled b\ Zacharias to he letrarch in A. Snh ////, [icnlareh or hexareh in A . />h{/Ilaii/jth<>/k>i, Hut in any one species the vascular system of the lip is letrarch. hui b\ Splitting of one or innre of xylem and phloem arms higher up. it usually heioines hcxareli. The i- li prolophloeiu palches (a)nsisl of a small central pateh ol' phloem cells, siirroimded liv sieve lubes. The protoxyleni consisls of a lew Spiral Iraeheae at Ihe lips of the arms, 1 li.it are sueeeeded cenlripelally bv eleinents Ihal heeonie greatl\ lignilied, and conslitiile a central tracheidal patch. |>y cambial formalion between Ihe protoxyleni and prolophloem, nietaxylem and at lirsl a limited aniouul of nietaphloein are laid down, along wilh i — ü uniseriale niediillary ravs. Siinultaneously Ihe pericamhiuni reorganizes as a cork eambiuni, aml begins to luv down cork. Succeeding death, and sloughing oll', of the cortex and epidermis oecur. The cork developed eonsisls of several layers annually, each formed of shallow cells of reddisb-yellow bue. Ihal give the characteristic eolor to the older rootlets. From Ihe second vear onward dei'ided addilions are made to

12 J. M. Macfarlane. — Nepenthaceae.

the metaphloem, which becomes a cylindrical zone of considerable width. The metaxylem develops the same elements as are to be treated of under the stem.

Stem system. The anatomy of the stem was studied by Schultz and Kor- thals, but more recently in a thorough manner by Zach arias. The following account confirms, and only in some points extends his observations, specially as pertaining to other species than those studied by him. Transverse sections of the stem of N. Hookeriana through the first internode beneath the expanding leaf, show a shallow epidermal layer with cuticularized walls. From it arise many multicellular hairs. Beneath are 3 — 4 layers of chlorophylloid cells with clear walls, succeeded by 12 — 14 layers of fibrous cells. These contain a few chloroplasts, and their walls are strongly thickened at the angles. Isolated spiral cells traverse the fibrous tissue at irregulär intervals. Beneath this is a zone of loose cortex tissue, composed of very unequal cells. Some of the smaller ones enclose small starch grains, some conglomerate crystals, a few contain chloroplasts, and some are spiral cells of rather large diameter. The endodermis (Fig. 5/") is a regulär layer of cells with thin walls. The cells contain small starch grains. Internal to it are 2 — 3 angular small-celled layers, succeeded by a relatively broad zone of large spiral cells, that are linked together by small thin-walled ones. Though thus peculiarly modified, if we accept present histological classifications, this double zone must be regarded as a highly specialized pericambial layer. The remaining plerome tissue within the last, indicates commencing modification along various lines. A relatively large amount in the centre is converted into pith tissue. This differentiates in part into thin-walled cells, that later may become filled with starch grains, and into large spiral cells. All of this tissue, as it continues to mature, so strikingly resembles that of the cortex, as to suggest a common origin embryologically with it. But later methods of wall thickening develop in the pith that cause it to differ strikingly from the cortex, while the conglomerate crystal cells of the latter have no parallel in the pith cells. The marginal mass of tissue beneath the pericambium differentiates into a ring of cambioid tissue, in which arise the proto-rudiments of the bundles. These are widely apart from each other, though they are