6. Epipremnum pinnatum (L.) Engl.

Species picture
Epipremnum pinnatum (L.) Engl. in Engl., Pflanzenr. 37 (IV.23B) (1908) 60 -- Pothos pinnatus L., Sp. Pl., ed. 2 (1763) 1374 (‘pinnata’) -- Monstera pinnata (L.) Schott, Wien. Zeit. Kunst, Literatur, Theater, Mode, 4th Quartal (127) (1830) 1028. -- Scindapsus pinnatus (L.)Schott in Schott & Endlicher, Melet. Bot. (1832) 21. -- Rhaphidophora pinnata (L.) Schott, Prod. Syst. Aroid. (1860) 385. -- Type: Appendix laciniata Rumph., Herb. Amb. 5 (1747) 489, t.183, f.2.Pothos pinnatifidus (‘pinnatifida’) Roxb., Fl. Ind. 1 (1832) 437. -- Monstera pinnatifida (Roxb.) Schott, Wien. Zeit. Kunst, Literatur, Theater, Mode, 4th Quartal (127) (1830) 1028. -- Scindapsus pinnatifidus (Roxb.) Schott in Schott & Endlicher, Melet. Bot. (1832) 21 (1832). -- Rhaphidophora pinnatifida (Roxb.) Schott, Prod. Syst. Aroid. (1860): 384 -- Type: Cultivated Calcutta Botanic Garden (no specimen traced).Pothos caudatus Roxb. Fl. Ind. 1 (1820): 476 (‘caudata’) -- Monstera caudata (Roxb.) Schott, Wien. Zeit. Kunst, Literatur, Theater, Mode, 4th Quartal (127) (1830): 1028 -- Scindapsus caudatus (Roxb.) Schott & Endlicher, Melet. Bot. (1832): 21 -- Rhaphidophora caudata (Roxb.) Schott, Prodr. Syst. Aroid. (1860): 382 -- Type: Cultivated Calcutta Bot. Gard. From specimens collected on Penang.Scindapsus forsteri Endl., Ann. Weiner. Mus. Naturgesch. 1 (1836) 161 – Type: ****.Scindapsus dilaceratus C. Koch & Sello, Ind. Sem. Hort. Bot. Berol. App., App. (1853) 5. -- Monstera dilacerata (C. Koch & Sello) C. Koch, Ind. Sem. Hort. Berol. App. (1855) 5. -- Tornelia dilacerata (C. Koch & Sello) Schott, Prodr. Syst. Aroid. (1860) 356. -- Rhaphidophora dilacerata(C. Koch & Sello) C. Koch, Gartenflora 5 (1864) ****. –Type: Cultivated Berlin Botanic Garden (B† holo; K iso), synons. nov.Epipremnum mirabile Schott, Bonplandia 5 (1857) 45. -- Type: Schott, Gen. Aroid. (1858) t.79.Rhaphidophora wallichii Schott, Prodr. Syst. Aroid. (1860) 383. – Type: Myanmar, Attran, Wallich 4437A (K holo; LE iso).Epipremnum elegans Engl., Bull. Soc. Tosc. di Ort. 4 (1879) 269. -- Types: Papua New Guinea, Soron, June 1872, Beccari PP 472 (FI syn; erroneously cited as PP 442 in protologue); Indonesia, Sulawesi Tengara, SE from Lepo-Lepo towards Kendari, July 1874, Beccari PS 46 (FI syn). Epipremnum crassifolium Engl., Bot. Jahrb. 25 (1898) 12. -- Rhaphidophora crassifolia (Engl.) Alderw., Bull. Jard. Bot. Buitenzorg III, 1 (1920): 382, comb. illeg. non R. crassifolia Hook.f., 1893 -- Rhaphidophora rosenburghii Furtado, Gard. Bull. Straits Settlem. 8 (1935): 8. -- Type: cultivated Bogor Botanic Garden 1896, Engler 4006 (B holo; B (spirit) iso), synons. nov. = MONSTERAEpipremnum mirabile Schott f. multisectum Engl., Bot. Jahrb. Syst. 25 (1898) 12. -- Epipremnum pinnatum (L.) Engl. f. multisectum (Engl.) Engl. in Engl., Pflanzenr. 37 (IV.23B) (1908) 63. -- Type: cultivated Bogor Botanic Garden 1896, Engler s.n. (B† holo).Rhaphidophora merrillii Engl., Bot. Jahrb. Syst. 37 (1905) 115. -- Types: Philippines: Mindanao, Davao, Mar. 1904, Copeland PNH 335 (B syn; K, PNH† isosyn); Philippines: Luzon, La Union, Bauang, Feb. 1904, Elmer PNH 5539 (B syn; K!, PNH† isosyn). As explained elsewhere in this paper, the Philippine populations of E. pinnatum require a separate study to resolve their status. Given the varied nature of the syntypes cited by Engler, no attempt at lectotypification will be made here.Epipremnum merrillii Engl. & K. Krause in Engl., Pflanzenr. 37 (IV.23B) (1908) 137. --Type: Philippines, Luzon, Zambales, Jan. 1907, Curran BS 5883 (B holo; PNH† iso).Epipremnum angustilobum K. Krause, Bot. Jahrb. Syst. 45 (1911) 659. -- Type: Philippines,Luzon, Benguet, Sablang, Nov.--Dec. 1910, Fenix 12587 (B holo; PNH† iso).Epipremnum elegans Engl. fma. ternatensis Alderw., Bull. Jard. Bot. Buit. ser.3, 4 (1922): 169. -- Type: Indonesia, Maluku. Pulau Ternate, Kota Baru (‘Baroe’), 13 Oct. 1920, Beguin 939 (BO holo)[Epipremnum glaucicephalum Elmer, Leafl. Philipp. Bot. 10(133): 3620 (1938). Voucher: Sorsogon, Irosin, Mt Bulusan, Nov. 1915, Elmer 15135 (BM, K, MO, P, PNH†), nom. inval.,descr. angl.]

Large root-climber to 15 m. Pre-adult plant usually forming modest terrestrial colonies. Adult plant with stem 5--40 mm diam., internodes 2--25 cm long, separated by quite prominent leaf scars, though these often obscured by prophyll, cataphyll and petiolar sheath fibre, stems lustrous green with prominent irregular longitudinal whitish crests, older stems with distinctive matt to sub-lustrous pale brown papery epidermis, flowering stems often with the terminal portion torn away from climbing substrate and ± plagiotropic. Clasping roots dense, feeding roots rather uncommon, usually strongly adherent to substrate, more rarely free, both root types pubescent, mid- to dark brown, growing tip pale brown-yellow, feeding roots later becoming prominently lenticellate. Cataphylls and prophylls soon drying and then degrading to prominent netted sheaths, these ± long-persistent and ± densely clothing upper stem before eventually decaying (but see Hay, 1990, pl. Xia). Foliage leaves somewhat scattered on lower stem, becoming somewhat clustered distally. Petiole 19.5--60 cm x 3--13 mm, canaliculate, smooth, dark green, air-drying mid- to dark brown and longitudinally sulcate; apical geniculum 16--70 x 3--5 mm, smooth, basal geniculum 3--7 x 1--1.5 cm, both genicula greater in diameter than petiole, drying shrunken to less than petiole diameter, dark and often with many lamellae-like ridges; petiolar sheath extending to half way along the apical geniculum, at first membranaceous, soon drying chartaceous, then disintegrating into untidy partially netted fibres, later falling to leave a ± smooth, mid-brown scar; lamina 10--93 x 5--60 cm, regularly pinnatifid to (rarely) entire, ovate to oblong-elliptic in outline, sub-membranaceous, apex acute to acuminate, base rounded to slightly cordate, divisions pinnatifid to pinnatisect, rarely midrib ± naked at sinus; pinnae 1.2--6.5 cm wide, apex truncate to acute, terminal pinna weakly sinuous, many individuals with minute to somewhat well developed pellucid dots especially adjacent to the midrib in leaves just beginning to display pinnae, pellucid dots often perforating and enlarging, sometimes extending to lamina margin (then fenestrations often additional to fully developed pinnae), lamina lustrous dark green, rarely slightly to intensely blue-green and glaucous above, paler beneath, pinnae each with 1 (rarely more except for the terminal pinna) compound primary lateral vein and several to rather many interprimary veins, these diverging from midrib at c. 75°, individual elements of the compound vein diverging at c. 10° from various points along the pinna, the compound vein becoming progressively finer towards the pinna tip, interprimary and secondary venation mostly remaining sub-parallel to compound primary vein, some weaker elements further dividing and becoming sub-reticulate, all higher order venation conspicuously reticulate, midrib impressed above, very prominently raised beneath, lower order venation slightly impressed to almost flush above, variously raised beneath, higher order venation flush above, flush or nearly so beneath in fresh material but raised and rather conspicuous in dried specimens. Inflorescence solitary, more rarely rarely two or more together, first inflorescence subtended by a usually fully developed foliage leaf and a very swiftly disintegrating cataphyll, at anthesis ± naked to partially or almost completely obscured by netted and sheet-like fibres. Peduncle 5.5--21.5 cm x 4--10 mm, stout, terete, pale green. Spathe canoe-shaped, stoutly attenuate to 15 mm, opening almost flat at anthesis, 7--23.5 x 3- 15 cm when pressed flat, exterior green, later dull greenish yellow to mid-green, interior dull yellow or pale green (reported as white by some collectors) at anthesis, air-drying dark brown, no detectable odour when fresh. Spadix 8.5--25 x 1.1--3.5 cm, sessile, cylindrical, bluntly tapering towards the apex, base slightly obliquely inserted, white when young, glaucous grey-green to greenish cream, dark yellow to green or greenish white at anthesis, air-drying almost black. Flowers 3--7 mm diam.; stamens 4; filaments 5 x 1 mm; anthers narrowly ellipsoid, 1.5--2 x 0.75--1 mm; ovary 4--12 x 2--7 mm, cylindrical, basal part slightly compressed; ovules 2--3; stylar region 3--7 x 1.5--4 mm, trapezoid, rather robust, apex flattened, margins somewhat raised in dry material; stigma linear, 2--6 x 0.1--0.5 mm, longitudinal. Fruit mid-green (prominently glaucous in Kostermans 21806, L!), stylar region greatly enlarged, ovary cavity with seeds embedded in sticky orange-red pulp; Seeds 4.5 x 3.5 mm, pale to mid-brown.

Distribution - Bangladesh, India (Andaman Islands), Myanmar, Thailand, Vietnam, Laos (?), China (Hainan), Hong Kong, Taiwan, Japan (Ryukyu Islands, Ogasawara Gunto [Bonin Islands]), Malaysia (Peninsular, Sabah, Sarawak), Singapore, Indonesia (Java, Maluku, Nusa Tenggara, Sulawesi, Sumatra), Philippines, Solomon Islands, Vanuatu, New Caledonia, New Guinea, Australia (Queensland), Marshall Islands, Belau Islands, Fiji, Tonga, Cook Islands, Western Samoa.

Habitat - Primary and secondary dense to open lowland to upper hill rain and monsoonal forest, weeds of rubber plantation, growing occasionally on rocks and in coastal forest, on a variety of substrate including granite, andesite and limestone. 1--1600m.

Notes - 1. Epipremnum pinnatum is a widespread and variable species; hence its extensive Malesian synonymy. However, there are several elements which, given more intensive study, might warrant taxonomic recognition. In particular various of these elements from the Philippines seem to differ by, e.g. consistently larger stature and pinnatisect leaf division. Current herbarium material is inadequate to resolve these plants’ status and more field observations are needed.
2. Sterile herbarium material lacking the pre-adult stage may prove difficult to distinguish from the complex of taxa centred on Rhaphidophora korthalsii Schott. Mature leaves of ‘typical’ R. korthalsii almost always have more than one primary lateral vein per pinna. The stems of R. korthalsii lack the prominent irregular whitish longitudinal crests and older stems the distinctive matt to sub-lustrous pale brown papery epidermis typical of E. pinnatum. The feeding roots of R. korthalsii are prominently scaly while those of E. pinnatum are lenticellate-corky. The pre-adult stage of R. korthalsii is a shingle climber with oblong-elliptic to ovate, slightly falcate upwards pointing leaves overlapping in the manner of roof tiles.
3. Fertile material of R. korthalsii and E. pinnatum is readily separated by the shape of the style apex (round to oval versus trapezoid) and the shape and orientation of the stigma (punctiform and circumferential versus linear and longitudinal) and, if fruits are mature, by seed characters. Epipremnum pinnatum has fruits with two large, strongly curved seeds with a bony and ornamented testa. The fruits of R. korthalsii each contain many small ellipsoid seeds with a brittle, smooth testa.
4. Epipremnum pinnatum also resembles Rhaphidophora tetrasperma, a species restricted to the northern Malay Peninsular (Perak, Kelantan) and the extreme south of Peninsular Thailand (Naratiwhat). Rhaphidophora tetrasperma has swiftly falling prophylls, cataphylls, and petiolar sheaths (e.g. ‘clean’ stems), a shingling juvenile stage and punctiform, circumferential stigmas.
5. Confusion may occur with between E. pinnatum and sterile Amydrium magnificum and A. zippelianum. The often quoted ‘difference’ between Epipremnum and Amydrium, that of reticulate versus parallel-pinnate higher order venation, is really a question of degrees of difference since both E. pinnatum and Amydrium have essentially the same venation patterns (parallel primary and reticulate higher veins). However, both A. magnificum and A. zippelianum have one primary lateral vein and two prominent interprimary veins (one on each side) per pinna; E. pinnatum has one primary lateral vein per pinna and the interpriamries are not particularly conspicuous. The leaflet tips of the Amydrium species are acute to acuminate, those of E. pinnatum truncate with the distal margin extended into a fragile thread of tissue. A further distinguishing feature concerns the petiolar sheath. Epipremnum pinnatum has the sheath extending to half way along the apical geniculum while in both the Amydrium the sheath only reaches to the top of the basal geniculum, the remainder of the petiole being terete with two sharply defined low keels running its length to merge with the base of the leaf lamina.
6. Croat & Grayum (1987) discussed Monstera dilacerata (C. Koch & Sello) C. Koch [syn. Scindapsus dilaceratus C. Koch & Sello, Tornelia dilacerata (C. Koch & Sello) Schott], a name applied by Madison (1977) to a number of different pinnatifid-leaved Monstera species (fide Croat & Grayum pers. comm.), and concluded that since the type specimen of the basionym (Scindapsus dilaceratus), deposited in Berlin, is missing and presumed lost, its true identity would probably remain unknown. However, N.E. Brown prepared a drawing of the type (K!) that shows it to be an exact match for the pre-adult stage of E. pinnatum, even to the pellucid dots next to the midrib. Further, on a copy (K!) of an article by Brown (1882) dealing with E. mirabile (= E. pinnatum) there is a note in the margin adjacent to the discussion of Monstera dilacerata, in Brown’s hand and dated April 1885, stating ‘I now believe that Monstera dilacerata, Koch is identified with Epipremnum mirabile Schott’. Grayum (pers comm.) reports a similar note, also in Brown’s hand, on a duplicate of E. pinnatum in MO. Scindapsus dilaceratus and its derived names are here added to the synonymy of the earlier E. pinnatum.
7. Rhaphidophora lacera Hassk., occasionally cited as synonymous with E. pinnatum is referable to Rhaphidophora pertusa (Roxb.) Schott, a species endemic to southern India and Sri Lanka (see Nicolson, 1988 & Hay, 1993 for discussion.)
8. Maliwanag (111, PNH!) notes that E. pinnatum is used to blacken the teeth.