Malesian Euphorbiaceae Descriptions

7. ANNESIJOA (Euphorbiaceae)

Hoang Van Sam & P.C. van Welzen

Hoang Van Sam & P.C. van Welzen. 2004. Revision of Annesijoa, Elateriospermum and

the introduced species of Hevea in Malesia (Euphorbiaceae). Blumea 49: 425–440.

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Genus description

Species descriptions

Annesijoa Pax & K. Hoffm.

Annesijoa Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.xiv (1919) 9; in Engl. & Harms, Nat. Pflanzenfam. ed. 2, 19c (1931) 101; Airy Shaw, Kew Bull. 14 (1960) 363, in key; Kew Bull. 16 (1963) 345; Hooker’s Icon. Pl. 37 (1967) t. 3632, p. 3, in observations; Hooker’s Icon. Pl. 38 (1974) t. 3713; Kew Bull. Add. Ser. 8 (1980) 27; G.L.Webster, Ann. Missouri Bot. Gard. 81 (1994) 104; Radcl.-Sm., Gen. Euphorbiacearum (2001) 293; Hoang Van Sam & Welzen, Blumea 49 (2004) 426; G.L.Webster in Kubitzki, Fam. Gen. Vasc. Pl. 11 (2014) 182. — Type: Annesijoa novoguineensis Pax & K. Hoffm.

Tree, monoecious. Latex variable, clear to white or red. Indumentum absent except for a few simple hairs in the domatia, and on the petals and ovary. Stipules not seen, also no scars, either absent or small and early caducous. Leaves alternate, digitate, 3–5(–7)-foliolate, young leaves red; petiole long, basally and apically pulvinate; petiolules basally slightly thickened; leaflets symmetric, base attenuately narrowing into the petiolule, margin subentire, slightly crenate because of widely spaced glands (serrulate when young); upper and lower surface smooth, lower surface with slightly hairy pocket domatia in the nerve axils; venation pinnate, flat above, raised underneath. Inflorescences axillary to pseudoterminal panicles with staminate or mixed flowers, usually in consecutive axils forming a kind of terminal compound panicle, several staminate flowers per side branch, one per node; pistillate flowers single, terminal on main branches; bracts minute. Flowers unisexual, actinomorphic; calyx 5-lobed, cupular, slightly imbricate; petals 5, free, imbricate, spathulate, white; disc glands 5 or 6. Staminate flowers: stamens 15–25, united in 3 layers; the outermost splitting off ﬁrst, the inner ones up to twice as long, free part of ﬁlaments short, anthers small, subglobose, 2-locular, basiﬁxed, opening latrorsely with lengthwise slits; pistillode absent. Pistillate flowers: pedicel more robust than that of staminate flower; calyx not persistent; disc glands very small, enlarging in fruit; ovary ovoid, densely sericeous (to sometimes glabrous), 3-locular; one ovule per locule; style absent to very short, stigmas 3, oblique, flat, strap-like, apically deeply bilobed. Fruit a subglobose capsule, pedicel elongating, glabrescent, completely dehiscing loculicidally, only partly so septicidally (basal part excepted), dark brown to black when ripe, with a rather thick, woody endocarp. Seeds usually 3 developing per fruit, ovoid but flattened ventrally, ridged ventrally and dorsally, ecarunculate.

Distribution — Monotypic, as the species.

Annesijoa novoguineensis Pax & K. Hoffm.

Annesijoa novoguineensis Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.xiv (1919) 9; Airy Shaw, Kew Bull. 14 (1960) 363, in key; Kew Bull. 16 (1963) 345; Hooker’s Icon. Pl. 37 (1967) t. 3632, p. 3, in observation; Hooker’s Icon. Pl. 38 (1974) t. 3713; Kew Bull. Add. Ser. 8 (1980) 27; Hoang Van Sam & Welzen, Blumea 49 (2004) 427, fig. 1, map 1. — Type: Ledermann 10873 (n.v., probably †), Papua New Guinea, Kaiserin Augusta Fluß-Expedition, (Hauptlager) Malu.

Tree, 15–40 m high, bole 10–33 m long, dbh 20–60 cm; buttresses absent to present, up to c. 1.3 m high and c. 50 cm wide. Outer bark c. 0.2 mm thick, smooth (to covered with many slightly raised lenticels), dark grey to grey-brown to brown; middle bark red to mottled red and cream to straw; inner bark 10–16 mm thick, straw to yellowish brown to red-brown, with some latex; sapwood c. 2 cm thick, white to brown; heartwood pink, moderately hard and heavy. Leaves: petiole 4–10(–20.5) cm long, round; petiolules absent to up to 2.5 cm long; leaflets elliptic to obovate, 5.5–23 by 2–6 cm, length/width ratio 2.7–3.5, chartaceous, base attenuate or acute, apex acuminate or rounded, upper surface green, drying greyish brown, lower surface light green, drying chestnut-brown; nerves 6–17 per side, looped and closed near the margin, veins widely reticulate to slightly scalariform. Inflorescences up to 18 cm long; branches up to 7.5 cm long; bracts triangular, c. 0.5 by 0.25 mm. Flowers with a pleasant fragrance; peduncle 0.5–5.5 cm long; petals obovate, margin entire, apex rounded. Staminate flowers 1.5–3.2 mm diam.; pedicel 5–12 mm long, calyx 2–3.2 mm deep, lobes ovate, 1–1.5 by 1–1.4 mm, veins inconspicuous; petals 5–8(–14) by 2–4 mm, hairy outside only, veins 5 or 6; disc glands obovate or elliptic, 1–1.2 by 0.3–0.8 mm; ﬁlaments 0.4–1.2(–3) mm long, thread–like; anthers 0.7–0.9 by 0.8–0.9 mm. Pistillate flower: pedicel 0.8–1.6(–2 in fruit) cm long, calyx 2–2.5 mm high, lobes ovate, 0.8–1.2 by 1–1.6 mm, veins inconspicuous; petals 8–13 by 4–5 mm, veins inconspicuous; disc glands obovate or elliptic, 0.4–1 by 0.3–0.7 mm; ovary 3–3.5 by 2.2–2.6 mm; stigmas 1–1.2 mm long. Fruits 2.5–3.5 by 2.1–2.6 cm, wall 2–2.7 mm thick, smooth. Seeds 10–12 by 7–11 mm, dark brown.

Distribution — Endemic in New Guinea.

Habitat & Ecology — Locally common in the canopy layer of dense primary, mixed forest with little undergrowth, disturbed forest, lower mountain Castanopsis-Oak rain forest. Altitude: 60–1370 m. Flowering twice per year: March to May, October to November; fruiting twice per year: January to February, June to August.

Vernacular names — Kovi-imi (Waskuk); Masjiw, sasor (Wandammen); Teweja / tweja (Kwerba); Umoo (Kilifas).

Note — The literature is not clear about the presence of latex in Annesijoa, while the specimens examined are variable and mention the latex to be slightly sticky to sticky, clear to white to red (LAE 51712, NGF 31831, Pullen 7319).