Apoballis belophylla (Araceae)
Herb to c. 60 cm tall. Stem epigeal, erect to decumbent, pleionanthic, 1–2 cm diam. with internodes to 2 cm long. Leaves c. 4 together; petiole 25–40 cm long, minutely and rather sparsely puberulent to papillate or glabrous, often tinged red, purplish or pink in the lower part, sheathing in the lower ¼–⅓; wings of sheath initially fully attached, tapering, soon degrading and deciduous especially in the upper part; blade matte dark green adaxially, sometimes glaucous, paler beneath, rather narrowly triangular, (somewhat ovato- to somewhat hasto-) sagittate, 14–36 cm long × 6–14 cm wide, the base deeply divided into two acute (finally narrowly rounded) posterior lobes 4–10 cm long with the sinus acute to obtuse; midrib somewhat prominent abaxially, with c. 9 primary lateral veins on each side regularly alternating with fine interprimaries and diverging at 45–70°; secondary venation rather inconspicuous abaxially and adaxially, arising from the midrib and from the primary veins, especially in the lower part of the blade; tertiary venation obscure. Inflorescences 1–2 together; peduncle hardly exserted from the subtending cataphylls, to c. 2⁄5 the length of the petiole; cataphylls lanceolate, to 9 cm long, soon degrading. Spathe 6–10.5 cm long; lower spathe greenish, 2.5–3.5 cm long, ovoid with a long neck (reaching the top of the interstice of the spadix), tapering 34 Telopea 9(1): 2000 into the limb but not differentiated from it by a constriction; limb narrowly oblonglanceolate, 3.5–7.5 cm long, whitish cream, barely opening, clasping the spadix, persisting after anthesis and finally falling with the spent parts of the spadix. Spadix subequalling the spathe, 5–8.5 cm long, subcylindric, sessile; female zone 1.5–2 cm long, c. 4 mm wide, obliquely inserted; pistils more or less crowded, ovoid to oblong, 0.5–1 mm diam.; stigma sessile, rather thick, discoid, c. 0.5 mm diam.; interpistillar staminodes lower and larger than the ovary, very few scattered among the pistils, a group at the base of the female zone, and a concentration of up to 8 irregular whorls above and adjacent to the uppermost pistils and forming the base of the interstice; interstice c. 1.5 cm long, covered at the base with aforementioned interpistillar staminodes, the rest naked but for small scattered groups of smaller staminodes and distally scattered sterile, incompletely fertile and fertile anthers; male zone cylindric, 1.2–1.5 cm long × 2–3 mm thick (dry); stamens crowded, truncate, dumbbell-shaped, c. 0.5 mm across, with the connective narrow and not or hardly elevated and the thecae with conspicuous annular rims; appendix 1.5–4 cm long, slender cylindric, about isodiametric with the male zone, finally tapering to an acute tip; staminodes of the appendix flat-topped, irregularly polygonal, c. 1 mm diam. Fruiting spathe ovoid with a pronounced neck, c. 4 cm long.
It can be distinguished from almost all species in the S. rupestris group by its narrowly triangular-sagittate leaves.
Malesia: endemic to Sumatera (confined to Aceh and North Sumatera provinces).
Terrestrial in sloping, well-drained sites in primary lowland to lower montane rainforest, occasionally on forest edge,