P. BOYCE, 2004 205 A Review of () in Cultivation

Peter Boyce Malesiana Tropicals Suite 9-04, Tun Jugah Tower No. 18, Jalan Tunku Abdul Ralunan 93100Kuching,Sarawak e-mail: [email protected]

ABSTRACT dinary variability of E. pinnatum and thus a tendency to disbelief that such radically A review of Epipremnum in cul­ different 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 name for E. aureum, a species often seen aureum, Epipremnum amplissimum, Epi­ offered from commercial sources as 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 (Queensland) and from climbing aroids is the presence of (Manipur) to the (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 typical of E. pinnatum while tivated aroid-and the golden variegated 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 zippelianum. 206 AROIDEANA, Vol. 27

The most easily observed distinguishing 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). dilacerata (K.Koch reaches only to the top of the basal genic­ & Sella) K.Koch, Index Seminum (B) ulum, the remainder of the 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 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 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 . 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 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 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 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. regularly, producing clusters of dull yellow spathed and (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, . 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 , 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. mooreense num compared with Rhaphidophora. is of the non-variegated form and it seems Nicolson's (Nicolson, 1978) paper dis­ likely that the golden variegated form in­ cussing E. aureum and E. pinnatum stated troduced into cultivation in the 19th Cen­ that he felt that there were insufficient dif­ tury was collected as a horticultural selec­ ferences for them to remain distinct spe­ tion. Such selections are common among cies and concluded by proposing that E. 19th Century plant introductions (e.g. Cod­ aureum be regarded as cultivar of E. pin­ iaeum, Poiyscias, etc.) at a time when natum. In the same paper Nicolson also plant hunters were often on the look out laid to rest the long-standing nomenclatur­ for horticultural novelties and furthermore al problems associated with the names frequently gave intentionally misleading Epipremnum and Rhaphidophora that information as to the origin of a potentially formed the cornerstone of Bakhuizen's pa­ important new horticultural introduction. per (Bakhuizen, 1958). Nicolson's 1978 ge­ Epipremnum aureum has a tortuous neric circumscription and cultivar status of nomenclatural history. It was first pub­ 'aureum' were incorporated into floras of lished as Pothos aureus Linden & Andre Fiji and (Nicolson, 1979, 1988), based on sterile juvenile material. The various checklists (e.g. Hay et al., 1995) choice of generic placement, notwith­ and revisions (e.g. Boyce, 1998). standing the manifestly different appear­ ance of the plant to any species of Pothos EPIPREMNUM AUREUM VS. as then circumscribed, remained unchal­ EPIPREMNUM PINNATUM lenged until Engler (in Engler & Krause, 1908) removed the species, still unflow­ There exists a suite of vegetative char­ ered, to Scindapsus, the generic choice acters that consistently separate E. pinna­ was influenced by the mature plant's over­ tum and E. aureum. In young pre-adult all appearance. There it remained until plants the leaf laminae are different in Birdsey (1962) reported the first recorded shape and texture. Those of E. aureum are flowerings, in Puerto Rico and at the Fair­ ovate to ovate-lanceolate and thicker in child Tropical Garden, Florida, and thus texture than the lanceolate to elliptic pre­ for the first time the critical charac­ adult leaves typical of E. pinnatum. As ters (several on an intrusive placen­ plants progress through the pre-adult ta) that showed the plant to belong to Epi­ stage and approach maturity more differ­ premnum sensu Engler & Krause (1908) ences become apparent. The distinctive although Birdsey chose to follow Bakhu­ netted sheath-remains, present in E. pin­ izen's (1958) unorthodox generic ideas natum, are absent in E. aureum while the and transferred Pothos aureus to Rhaphi­ leaf lamina 'pin-holes' characteristic of E. dophora as R. aurea. pinnatum are far fewer in number, do not Furtado (964), seemingly unaware of develop to any degree and hardly ever Birdsey's publication, published the same perforate, while leaf division by means of combination when reporting the flowering pinnation is sporadic and occurs only as of "P. aurea" in Singapore. Furtado based solitary to few irregular rather shallow pin­ his generic placement upon D.H. Nicol­ nations. Leaf texture remains consistently son's hand-written annotations to Engler & thicker than for E. pinnatum and leaf lam­ Krause's (1908) key; Nicolson at that time ina shape remains more or less constant, also following Bakhuizen's generic con­ the lamina simply increasing in size and cepts. not perceptibly altering shape. Massive fla­ Bunting (964), transferring Pothos au­ gellate foraging shoots develop, often in reus to Epipremnum, remarked that ''jlow- some quantity, and a profusion of promi- P. BOYCE, 2004 209 nently lenticellate robust feeding roots is 'Hawaiian' produced, many of which remain hanging 'Hawaiian' is very close in appearance free and reach the ground. Overall the to 'Wi!coxii' in having leaves with dense plants are considerably more robust and but fragmented yellow variegation. produce many climbing stems (E. pinna­ tum is generally noticeably less robust and few-stemmed). 'Jade' Most literature emphasises the shy-flow­ 'Jade' has plain rich green leaves and ering nature of E. aureum. Enquiries at may to equate with reverted 'Aureum', Bogor confirmed that the numerous plants which in turn is indistinguishable from cultivated there of both the variegated and wild type (i.e. Moorea) E. aureum, al­ the wholly green plants of E. aureum are though the heavier textured leaves of the shy flowering. This is in marked contrast juveniles also suggest that it may be a re­ to E. pinnatum, which flowers profusely version of 'Marble Queen'. 'Tropic Green' wherever it occurs in the wild and in cul­ is very close in appearance to 'Jade'. 'jade tivation. Pothos' is indistinguishable.

CULTIVATED FORMS 'Johanna Queen' (VKC registered 8 On the whole no formal attempt will be April 1993) made to support or otherwise the veracity 'Johanna Queen' has dark green leaves of a cultivar name except to state, as ap­ with irregular pale green marbling. Rare in propriate, the registration date with the cultivation and seemingly not currently Vaste Keurings Commissie (VKC) and commercially available. where the distinctness of particular cultivar would not perhaps withstand close SCfll­ 'Marble Queen' (VKC registered 28 tiny. July 1988) 'Aureum' (VKC registered 28 July 'Marble Queen' is, after 'Aureum', the 1988) cultivar most often grown in . The Equating to the typical plant, although leaves are variegated in the same manner this is not to imply that 'Aureum' in culti­ as 'Aureum' except that the yellow color­ vation can be traced back to Linden's orig­ ation is replaced with pale cream or white. inal introduction. As a juvenile this plant The stems are marbled cream or white on has leaves that are variegated with large, green. I have not seen a mature plant of discrete jagged golden yellow patches 'Marble Queen'. over dark green. As plants reach adult­ hood the yellow leaf markings increase in 'Mayan Gold' area until in mature individuals leaves are Clear golden yellow leaves. Very similar not infrequently for the most part yellow. to 'Golden Pothos' although the leaf color Stems are variegated with yellow marbling is richer. over green. 'Neon' 'Golden Pothos' (VKC registered 13 September 1990) 'Neon' has acid green-yellow leaves without any other markings. The stems are A cultivar with wholly clear golden yel­ slightly darker in color. low leaves and stems. Mature plants 'Gold­ en Pothos' are rare in cultivation. It is per­ 'Tropic Green' haps unfortunate that the registered name should utilize 'Pothos' and thus, however 'Tropic Green' is a plain green leaved obscurely, imply some form of relation­ cultivar close to wild type E. aureum. Per­ ship to Pathos. haps the same as 'Jade' 210 AROIDEANA, Vol. 27

'Wilcoxii' most readily recognizable species by virtue of the bright green thinly cori­ 'Wilcoxii', while similar to 'Aureum', has aceous oblong leaf lamina with prom­ dense yellow variegation that is much inent, dense, striate venation. more fragmented, giving the leaf a golden­ Specimens in shade tend towards 'leg­ and green-marbled appearance. 'Wilcoxii giness' with widely separated leaves Gold' is indistinguishable. and duller leaf laminae but specimens Epipremnum amplissimum (Schott) in exposed situations exhibit a dense Engl., Bot. jahrh. Syst. 1: 182 (1881). habit with the leaf colour intensified Rhaphidophora amplissima Schott, to emerald green and further en­ Ann. Mus. Bot. Lugduno-Batavi 1: 129 hanced by a red or yellow tint taken (1863). on by the hyaline margin of the lam­ Rhaphidophora chevalieri Hort. non Gag- ina. Such plants are most attractive. nep. This is the only Epipremnum species Rhaphidophora chevalieri 'Exotica' that seems to regularly on both Rhaphidophora 'Exotica' clinging and free stems (even on the Scindapsus siamensis Hort. non. Engl. same plant, Boyce & Hay indepen­ Scindapsus 'Exotica' dent pers. obser.). The inflorescences are solitary with the newly opened Epipremnum amplissimum is most of­ spathe deep golden yellow and pro­ ten cultivated as a pre-adult plant at which duce a strong smell of peanut butter. stage the narrowly elliptic rather soft-tex­ Not common in cultivation, although tured leaves are jagged pale bluish grey large (usually unidentified) plants are splashes. As the plant matures the leaves occasionally seen in old established become longer and broader and develop collections, especially in Florida. a harder texture while the variegation mostly disappears, although occasionally a mature plant of E. amplissimum may re­ LITERATURE CITED tain some traces of these grey markings. Bakhuizen van den Brink, R. C. 1958. Are Plants of Epipremnum amplissimum ap­ Epipremnum Schott, Rhaphidophora pear in the trade under a variety of names Hassk. And Monstera Adans. conge­ the origins of which are obscure although neric? Blumea suppl. 4:91-92. 'Exotica' and 'siamensis Exotica' both ap­ Birdsey, M. R. 1962. Pothos aureus Trans­ pear in editions of Grafs Exotica. Most of ferred to Rhaphidophora. Batleya 10: the names imply an origin in Thailand or 155-159. Vietnam (R. chevalieri is a quite different Boyce, P. C. 1998. The Epipremnum species from Vietnam) but in fact E. am­ Schott (Araceae-­ plissimum is native to New Guinea, the Monstereae) in West and Central Ma­ western tropical Pacific and far east as Va­ lesia. Blumea 43:183-213. nuatu and scattered localities in Northern Bunting, G. S. 1964, '1963' Studies in Ara­ Australia. ceae. Ann. Missouri Bot. Gard. 50:23- Epipremnum giganteum (Roxb.) Schott, 28. Bonplandia 5 (1857) 45. Pothos gi­ Engler, A. & K. Krause. 1908. Araceae­ gantea Roxb., Fl. Ind. 1: 455 (1820). Monsteroideae. In A. Engler (ed.), Monstera gigantea (Roxb.) Schott, Das Pjlanzenreich 37 IV.23B:4-139. Wiener Z. Kunst 4: 1028 (1830). Scin­ Furtado, C. x. 1964. Pothos aurea, Hort. dapsus giganteus (Roxb.) Schott in Linden. Gard. Bull., Singapore 20: H.W.Schott & S.L.Endlicher, Melet. 377-380. Bot.: 21 (1832). Rhaphidophora gi­ Hay, A., J. Bogner, P. C. Boyce, W. L. A. gantea (Roxb.) Ridi., Mat. FI. Mal. Hetterscheid, N. Jacobsen &J. Murata. Pen. 345 (1907). 1995. Checklist & Botanical Bibliog­ Epipremnum giganteum is one of the raphy of the Aroids of Malesia, Aus- P. BOYCE, 2004 211

tralia and the Tropical western Pacific. Pacific Tropical Botanic Garden, La­ Blumea suppl. 8, pp. 210. wai, Kauai, HI. Nicolson, D. H. 1978. Araceae, In A. C. ---. 1988. Araceae, In M. D. Dassan­ Smith (ed.), Precursor to a New Flora ayake & F. R. Fosberg (eds.), A Re­ of Fiji. Allertonia 16:345-348. vised Handbook to the Flora of Cey­ ---. 1979. Araceae, In A. C. Smith lon, 6:17-101. Balkema, Rotterdam. (ed.), Flora Vitiensis Nova, 1:438-460.