Philodendron williamsii Hook.f.

STEM: erect to decumbent, branching in horizontal portion, erect portion 50-120 cm tall, stout and trunk-like, 5-8.5 cm thick; adventitious roots c. 1.5 cm thick; internodes less than 1 mm long; prophyll scars longer than true internodes, c. 5 mm long; intravaginal squamules 1-2 mm long or less, c. 1 -2 mm broad, triangular or multitoothed, inconspicuous, persistent; foliage leaf scars subcircular to transverse-elliptic, c. 4 cm long, 4-5 cm wide, lighter than rest of stem surface. LEAF: prophyll subequal to petioles of new leaves, yellow-green; petiole 50-92 cm long, 0.8-1.5 cm diam. at apex, broadly sulcate adaxially with sharply angled to rounded margins and sometimes with slight central ridge, sometimes minutely verruculose, sheath 8-16 cm long; leaf blade elongate-sagittate, margin repand, overall length 62-100 cm, overall width (24-)28-44 cm, upper surface mid green with paler green primary lateral veins, lower surface paler green with yet paler and pinkish flushed primary lateral veins; anterior division 39-70 cm long, 16-44 cm wide, widest at base, apex acute to obtuse with acuminate tip, primary lateral veins 3-5(-6), usually 4 per side, more spaced out towards leaf apex, arising at an angle of 50-90°, cross veinlets between finest parallel veins often quite distinct in dried material; posterior divisions 20-34 cm long, 0.3(-0.4) x overall blade length, (12-)14-21 cm wide, retrorse to slightly introrse, basal ribs denuded for (3 -)4-6.5 cm, tip acute and ± rounded at extremity, primary acroscopic veins (1 -)2-3(-4), primary basiscopic veins (0-)l -4(-5), basiscopic lamina area well developed, ± overlapping. INFLORESCENCE: peduncle 8.5-14(-30?) cm long, 2-4 cm diam. at apex, either enclosed almost entirely in petiole sheath or (fide Hooker) as long as spathe: spathe 20-30 cm long, 4-8 cm diam. at middle, decurrent for 2.5-5 cm long, outer surface glossy green with darker fine veins, dotted here and there with minute pale brown extrafloral nectaries, inner surface pale yellowish-white; spadix 18.5-30 cm long, white, fertile male zone 5.5-6.5 cm long, 2-2.8 cm diam., subellipsoid, sterile male zone 8-8.5 cm long, 1.4-3 cm diam., upper region sometimes narrower than adjacent fertile male zone, female zone 3.5-5 cm long, 2.2-3.5 cm diam. FLOWERS: stamens 7-7.3 mm long, 1-1.4 mm diam. at apex; staminodes 6.5-7.5 mm long, 2.2-3.8 mm diam. at apex, always ± clavate, apex sometimes rounded, usually flattened, narrowing abruptly just below apex or tapering gradually; gynoecium 9-15.5 mm long, ovary + flask-shaped. 4.5-5.5 mm long, 3-4.8 mm diam., raphides very numerous in septa and inner walls, at least in apical part of ovary, or extending also to base, locules 12-13 per ovary, ovules 3-4 per locule, inserted from base to about middle of axis, evenly spaced, style body lacking since compitum penetrates well down into ovary axis, style crown very elongated, extending for up to 9-10 mm beyond ovary locules, ¿lacking tannin, style lobes at apex weakly or not at all evident externally but running down inside as distinct ridges covered with stigmatic papillae almost to base of compitum, central dome present, extending to apex of style crown or slightly less, stylar canals very short, entering locules about halfway down, stigma 4.2-6 mm diam., sometimes with many tannin hairs, covering style crown lobes when these are well-developed {Williams s.n.) or ± confined to style funnel when lobes are not well-developed {Harley et al. 18501). INFRUCTESCENCE: berry shortly compressed-cylindric, 1.6-1.7 cm long, 1.3-1.5 cm diam., pale orange, style fleshy and persistent; seed ovoid-subcylindric, 5-5.5 mm long, 2.8 — 3.1 mm diam., pointed at micropylar end, buff white testa very fleshy, forming a ± opaque sarcotesta surrounding subcylindric inner body containing endosperm and embryo.