P. BOYCE, 2004 205 A Review of Epipremnum (Araceae) in Cultivation Peter Boyce Malesiana Tropicals Suite 9-04, Tun Jugah Tower No. 18, Jalan Tunku Abdul Ralunan 93100Kuching,Sarawak Malaysia e-mail: [email protected] ABSTRACT dinary variability of E. pinnatum and thus a tendency to disbelief that such radically A review of Epipremnum species in cul­ different plants can belong to the same tivation is presented in order to clarify species, a problem exacerbated by the their identities and the names that should radically different appearance of the ju­ be applied. venile and adult phases of this species, and in part due to the great reluctance of KEYWORDS nurseries to accept and utilize the current Epipremnum pinnatum, Epipremnum name for E. aureum, a species often seen aureum, Epipremnum amplissimum, Epi­ offered from commercial sources as Pothos premnum giganteum, Araceae. aureus Linden & Andre, a name obsolete now for more than 120 years. INTRODUCTION IDENTIFICATION Epipremnum Schott comprises 14 spe­ cies of slender to gigantic root-climbing Ii­ The key character to distinguish E. pin­ anes distributed from S. Japan CRyukyu Is.) natum and E. aureum from aU other to Australia (Queensland) and from India climbing aroids is the presence of (Manipur) to the Cook Islands (Raroton­ prominent irregular longitudinal whitish ga). The widespread E. pinnatum (1.) ridges along the stems. Eng\. accounts for most of these distribu­ Non-flowering adult plants can be con­ tional extremes while the remaining spe­ fused with (in cultivation much rarer) Rha­ cies have a more restricted natural range. phidophora korthalsii Schott. The stems of Variegated clones of E. aureum (Linden R. korthalsii lack the prominent irregular & Andre) G.S. Bunting are extremely pop­ whitish longitudinal ridges and distinctive ular as cultivated plants worldwide-per­ matte to sub-lustrous pale brown muricate haps constituting the most commonly cul­ epidermis typical of E. pinnatum while tivated aroid-and the golden variegated leaves of R. korthalsii almost always have form of this species is frequently met with more than one primary lateral vein per as an escape from horticulture throughout pinna. The feeding roots of R. korthalsii the tropics. are prominently scaly while those of E. Two additional species are occasionally pinnatum are lenticellate-corky. The pre­ found in cultivation, E. amplissimum adult stage of R. korthalsii is a shingle (Schott.) Eng\. and E. giganteum (Roxb.) climber with oblong-elliptic to ovate lam­ Schott. inae that are slightly falcate, directed up­ Considerable misapplication of names wards and overlap in the manner of roof exists in horticulture with regard in partic­ tiles. ular to E. pinnatum and E. aureum. This Confusion is also possible between E. obfuscation is due in part to the extra or- pinnatum and Amydrium zippelianum. 206 AROIDEANA, Vol. 27 The most easily observed distinguishing Scindapsus forsteri Endl., Ann. Wiener feature concerns the petiolar sheath. Epi­ Mus. Naturgesch. 1: 161 (1836). premnum pinnatum has the sheath ex­ Scindapsus dilaceratus KKoch & Sella, In­ tending to half way along the apical ge­ dex Seminum (B) 1853(App.): 5 niculum while in Amydrium the sheath (1853). Monstera dilacerata (K.Koch reaches only to the top of the basal genic­ & Sella) K.Koch, Index Seminum (B) ulum, the remainder of the petiole being 1855(App.): 5 (1855). Tornelia dila­ terete with two sharply defined low keels cerata (KKoch & Sello) Schott, Prodr. running its length to merge with the base Syst. Aroid.: 356 (1860). Rhaphido­ of the leaf lamina. Amydrium zippelianum phora dilacerata (KKoch & Sella) has one primary lateral vein and two KKoch in E.von Regel, Gartenflora: 5 prominent interprimary veins (one on (1864). each side) per pinna; E. pinnatum has one Epipremnum mira bile Schott, Gen. Aroid.: primary lateral vein per pinna and the in­ t. 79 (1858). terprimaries are not particularly conspicu­ Rhaphidophora wallichii Schott, Prodr. ous. The leaflet tips of the Amydrium spe­ Syst. Aroid.: 383 (1860). cies are acute to acuminate, while those of Rhaphidophora cunninghamii Schott, E. pinnatum are truncate with the distal Bonplandia 9: 367 (1861). margin extended into a fragile thread of Rhaphidophora vitiensis Schott, Bonplan­ tissue. dia 9: 367 (1861). Rhaphidophora per­ tusa (Roxb.) Schott var. vitiensis Epipremnum pinnatum (L.) Engl. in (Schott) Engl. Engl., Pjlanzenr., IV, 23B: 60 (908). Scindapsus bipinnatifidus Teijsm. & Binn., Pothos pinnatus L., Sp. PI. ed. 2: 1324 Cat. Hart. Bot. Bogar.: 65 (1866). (1763). Monstera pinnata (L.) Schott, Epipremnum elegans Engl., Bull. Soc. Wiener Z. Kunst 4: 1028 (1830). Scin­ Tosc. Ortic. 4: 269 (1879). dapsus pinnatus (L.) Schott in Philodendron dilaceratum Engl. in & H.W.Schott & S.L.Endlicher, Melet. A.L.P.de Candolle AC.P.de Can­ Bot.: 21 (1832). Rhaphidophora pin­ dolle, Monogr. Phan. 2: 265 (1879). Rhaphidophora lovellae F.M.Bailey, nata (L.) Schott, Bonplandia 5: 45 Queensland Agric. 1: 453 (1897). (1857). J. Epipremnum mirabile f. multisectum Polypodium laciniatum BurmJ., Fl. Engl., Bot. Jahrb. Syst. 25: 12 (1898). Indica: 231 (1768). Rhaphidophora Epipremnum pinnatum f. multisec­ laciniata (BurmJ.) Merr., Philipp. J. tum (Engl.) Engl. in Engl., Pflanzenr., Sci. 19: 342 (921). IV, 23B: 63 (1908). Pothos caudatus Roxb., FI. Ind. 1: 476 Epipremnum mirabile Schott f. eperfora­ (1820). Monstera caudata (Roxb.) tum Engl., Bot. Jahrb. Syst. 25: 12 Schott, Wiener Z. Kunst 4: 1028 (1898). Epipremnum pinnatum f. (1830). Scindapsus caudatus (Roxb.) eperJoratum (Engl.) Engl. in Engl., Schott in H.W.Schott & S.L.Endlicher, Pflanzenr., IV, 23B: 63 (1908). Melet. Bot.: 21 (1832). Rhaphidopho­ Rhaphidophora merrillii Engl., Bot. Jahrb. ra caudata (Roxb.) Schott, Prodr. Syst. 37: 115 (1905). Syst. Aroid.: 382 (1860). Epipremnum merrillii Engl. & KKrause in Pothos pinnatifidus Roxb., FI. Ind. 1: 476 Engl., Pflanzenr., IV, 23B: 137 (1908). (1820). Monstera pinnatifida (Roxb.) Epipremnum angustilobum KKrause, Bot. Schott, Wiener Z. Kunst 4: 1028 Jahrb. Syst. 45: 659 (1911). (1830). Scindapsus pinnatifidus Epipremnum robinsonii K.Krause, No­ (Roxb.) Schott in H.W.Schott & tizbl. Konigl. Bot. Gart. Berlin 5: 266 S.L.Endlicher, Melet. Bot.: 21 (1832). (1912). Rhaphidophora pinnatifida (Roxb.) Epipremnum formosanum Hayata, Icon. Schott, Bonplandia 5: 45 (1857). PI. Formosan. 5: 239 (1915). Rhaphi- P. BOYCE, 2004 207 dophora formosana (Hayata) M. whether the leaf shape is maintained to Hotta, Mem. Fac. Sci. Kyoto Univ., adulthood. Ser. BioI. 4: 83 (1970), nom. illeg. Epipremnum elegans Engl. fma. ternaten­ 'New Guinea' sis Alderw., Bull. Jard. Bot. Buit. ser.3, 4: 169 (1922). A cultivar in which the small deep Rhaphidophora neocaledonica Guillau­ green, glossy leaves are profusely micro­ min, Bull. Soc. Bot. France 84: 160 perforated but never pinnately divided. (1937). Most often seen as a juvenile, this plant Epipremnum glaucicephalum Elmer, will readily begin to climb and reach adult­ Leafl. Philipp. Bot. 10(133): 3620 hood at which stage the leaf size increases (1938). nom. inval., descr. anglo but still no division occurs. This plant orig­ inates from western Papua New Guinea. CULTIVATED FORMS MISAPPLIED NAMES The most commonly cultivated form of E. pinnatum has dark green semi-glossy 'Ginny' adult leaves that are broadly elliptic-ob­ Epipremnum pinnatum 'Ginny', Philo­ long with copious pinnations and micro­ dendron imbe 'Ginny' and 'dwarf Mon­ perforations. It is a vigorous climbing stera pertusa' are all referable to Rhaphi­ plant, easily reaching 5 m where a suitable dophora tetrasperma Hook.f. a species re­ climbing surface is provided. Once mature stricted to Peninsular Malaysia (Kelantan, (climbing to more than 2 m) this form Perak) and southern Thailand. flowers regularly, producing clusters of dull yellow spathed inflorescences and Epipremnum aureum (Linden & Andre) then fruiting prolifically. It is not clear from G.S. Bunting, Ann. Missouri Bot. where this form originates although veg­ Card. 50: 28 (1964, '1963'). Epiprem­ etatively it is close in appearance to E. pin­ num pinnatum (1.) Engl. cv. Aureum natum from Luzon, Philippines. There ap­ (see Nicolson, Allertonia 1: 347, pears to be no cultivar name applied to 1978). Pothos aureus Linden & Andre, this form. Ill. Hort. 27: 69 (1880). Scindapsus aureus (Linden & Andre) Engl. in 'Cebu Blue' Engl., Pflanzenr. 37 OV.23B): 80 (1908). Rhaphidophora aurea (Lin­ A cultivar with pale blue-grey leaves, den & Andre) Birdsey, Baileya 10: 159 the colour intensifying in bright light. The (1963, '1962'). Rhaphidophora aurea leaf blade is narrowly elliptic with a few, (Linden & Andre) Furtado, Gard. Bull. deep (nearly reaching the mid-rib) divi­ Singapore 20: 379 (1964), comb. su­ sions per side and only few micro-perfo­ perfl· rations. Inflorescences are produced singly Epipremnum mooreense Nadeaud, J. de or in pairs. The spathe interior is pale Botanique 13:6 (1899). green. This plant originates from Cebu Is­ land, Philippines. ORIGINS 'Key Leaf' The type description of Pothos aureus states that the original plant came to Lin­ A juvenile form in which the greater den's nursery from the Solomon Islands, portion of the leaf blade is reduced to a but this cannot be substantiated; certainly long, narrow strip of undulating tissue plants equating to E. aureum have never along either side of the mid rib and ex­ to my knowledge been collected as wild panding to form the basal lobes, the whole plants in the Solomon Islands. However, leaf resembling a key. I have not seen the the wild provenance of E. aureum was re­ adult stage of this plant and do not know cently resolved following examination of 208 AROIDEANA, Vol. 27 the type of Nadeaud's Epipremnum moo­ ering material is very similar to that qf E. reense, a plant collected from natural for­ pinnatum, and must be included in that est on Moorea (French Polynesia) and genw,~' and went on to reiterate the char­ which is clearly identical with E. aureum acters he regarded as distinct for Epiprem­ as here defined. The type of E.