10. Pothos curtisii Hook.f..

Pothos curtisii Hook.f., Fl. Brit. Ind. 6 (1893) 554 — Syntypes: Malaysia, Perak, Larut, Kunstler (‘Dr King’s collector’) 3887 (K!); Malaysia, Perak, Larut, Kunstler (‘Dr King’s collector’) 4221 (K); Malaysia, Penang, Batu Ferringgi, Curtis 808 (K!); Malaysia, Perak, Scortechini 624a (K!). Pothos peninsularis Alderw., Bull. Jard. Bot. Buitenzorg 3, 1 (1920) 381. syn. nov.— [Pothos latifolius Hook.f., Fl. Brit. Ind. 6 (1893) 554 (1893), nom. illeg., non Pothos latifolius L. (1759) (Maluku)] — Syntypes: Malaysia, Perak, Larut, Kunstler (‘Dr King’s collector’) 3903 (K!); Malaysia, Perak, Thaiping (Taiping) Larut, Kunstler (‘Dr King’s collector’) 8493 (K!). Pothos kunstleri Hook.f., Fl. Brit. Ind. 6 (1893) 554, syn. nov. — Syntypes: Malaysia, Perak, Larut, Kunstler (‘Dr King’s collector’) 2754 (K!); Malaysia, Perak, Larut, Sunkei (‘Sunkei Perak’), Kunstler (‘Dr King’s collector’) 3012 (K!, SING!). Pothos maingayi Hook.f., Fl. Brit. Ind. 6 (1983) 554, syn. nov. — Syntypes: Malaysia, Malacca, 1867 – 1868, Maingay 1538 (fl.) (K!) & Maingay 3041 (fl.) (K!).

Slender heterophyllous root-climbing liane to 3 m. Eocaul not observed; stem of juvenile shoot to 1.5 mm diam., terete to slightly angled in cross section, shingle-leaved; stem of mature sterile shoot to 6 mm diam., terete in cross section, mid-green becoming brown with age, leaves scattered, spreading, eventually becoming naked, nodes 7 – 50 mm distant, mid-green; stem of fertile shoot to 4 mm diam., terete in cross section. Leaves when fresh mid-green, paler abaxially, air dried material mid-green to brown; petiole 20 – 105 x 1 – 6 mm, slender, canaliculate, rounded abaxially, base decurrent, apex prominently geniculate,older geniculum corky; sheath distinct, prominent, erect, apically ligulate in young growth, ligule later disintegrating, base amplexicaule or decurrent to almost free; lamina 80 – 260 x 16 – 95 mm, broadly to narrowly oblong elliptic, 2 intramarginal veins per side, 2 – 13 mm from lamina margin, arising from just above base of the midrib, remaining ± parallel to margin, terminating at the tip of the lamina, base obtuse, apex acuminate to long-acuminate, apiculate, apicule later deciduous. Flowering shoot much abbreviated to rarely rather elongated through reiteration, (foliage) leafless or, occasionally, bearing developed but undersize foliage leaves. Inflorescence solitary on a reiterating flowering shoot; peduncle 25 – 65 x 1 – 4 mm, somewhat robust, strongly curving or straight, the inflorescence held erect, mid-green; spathe 34 – 67 x c. 10 mm, linear-triangular to narrowly oblong, base rounded, annularly inserted onto peduncle, apex acuminate, slightly rough to smooth, pale brown tinged reddish pink; spadix stipitate; stipe 3 – 19 x 1 – 2 mm, terete; fertile portion 35 – 135 x 0.5 – 3 mm, very slender-cylindric, occasionally sterile at the tip, pale greyish pink, older inflorescences blackish red. Flowers 3 x 2.1 x 1.6 mm diam., widely scattered, arranged in a lax spiral along the spadix; tepals 1.4 x 1.1 mm, broadly ovate to fornicate, basal portion considerably thickened, excavated, margins hyaline, erose, abaxial surface umbonate; stamens 0.75 – 0.87 x 0.5 mm mm at anthesis, filaments strap-shaped, thecae 0.25 x 0.25 mm, oblong-ellipsoid, yellow; ovary 0.5 x 1.13 mm, compressed-globose to hexagonal-turbinate; stylar region massive, truncate; stigma prominent, punctiform. Infructescence not observed.

Distribution — Indonesia (Sumatera), Peninsular Malaysia, Singapore, Thailand.

Habitat & Ecology — Wet hill and lowland evergreen forest. 60 – 600 m.

Notes — For such a distinctive species (the only representative of the remarkable ‘luzonensis group’ in continental SE Asia) P. curtisii has a chequered taxonomic history; three of its four synonyms were described on the same page of the Flora of British India. Of these synonyms P. latifolius Hook.f. (the name most often applied to P. curtisii) is illegitimate, being preceded by P. latifolius L. Alderwerelt was aware of this and published a new name, P. peninsularis (Alderwerelt 1920), for Hooker’s P. latifolius. However, Alderwerelt had apparently not appreciated that Hooker had described the same species under four different names. In synonymizing Hooker’s names one has to take account that have priority over that proposed by Alderwerelt. Accordingly I have selected the name P. curtisii as the collection with the best syntypes from which to lectotypify the name.
In the review region P. curtisii is known from a single collection from an unnamed grid reference (see Jacobs 1962). The label cites ‘Bukit’ (the Malay word for hill) but I have been unable to trace such a place and assume that Put was simply indicating a hill in the region of the Thai – Kedah (Malaysian) border.
Pothos curtisii is the only species of the luzonensis group (see Hay & Boyce 1998) occurring in the review area and fertile material is unmistakable by the slender spadix and scattered flowers. Sterile specimens may be confused with other species of subgen. AlloPothos, especially those occurring in the same region of peninsular Thailand (e.g. P. kingii and P. lorispathus). Pothos lorispathus and P. kingii have thinly chartaceous leaves, while P. curtisii has more coriaceous leaves.

Specimen studied:
THAILAND. PEN76. Narathiwat: Bukit (hill) at 006° 10’N, 101° 50’E, 24 Jan. 1931, Put 3615 (fl.) (K).