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Malesian Euphorbiaceae Descriptions |
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Esser, H.-J. 1999. A partial revision of the Hippomaneae (Euphorbiaceae) in Malesia. Blumea 44: 149–215.
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Stillingia Garden ex L., Mant. (1767) 19; Syst. Nat. ed. 12, 2 (1767) 637; A.Juss., Euphorb. Gen. (1824) 49; Benth. in Benth. & Hook.f., Gen. Pl. 3 (1880) 334; Pax in Engl. & Prantl, Nat. Pflanzenfam. 3, 5 (1890) 96, fig. 61, 62; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.v (1912) 180; in Engl. & Harms, Nat. Pflanzenfam. ed. 2, 19c (1931) 198; D.J.Rogers, Ann. Missouri Bot. Garden 3 (1951) 207; G.L.Webster, J. Arnold Arbor. 48 (1967) 388, fig. 5; Ann. Missouri Bot. Gard. 81 (1994) 122; Esser, Blumea 44 (1999) 193; in Radcl.-Sm., Gen. Euphorbiacearum (2001) 370; G.L.Webster in Kubitzki, Fam. Gen. Vasc. Pl. 11 (2014) 203. — Stillingia sect. Eustillingia Klotzsch ex Baill., Étude Euphorb. (1858) 510, nom. inval.; Müll.Arg. in DC., Prodr. 15, 2 (1866) 1155. — Sapium sect. Stillingia (Garden ex L.) T.Post & Kuntze, Lex. Gen. Phan. (1903) 498. — Type: Stillingia sylvatica Garden ex L.
Shrubs to trees (succulent in Ser. Dichotomae, some Neotropical species perennial herbs). Monoecious. Flowering and fruiting twigs with leaves. Indumentum absent. Stipules ovate-triangular with a long acumen, less than 2 mm long, often divided into several ciliae, basally glandulous. Leaves alternate, sometimes apically crowded (opposite in some Neotropical species); petiole short (less than 2 cm long), much shorter than blade, glandless or apically with a pair of conspicuous to inconspicuous (even stipitate in some Neotropical species) glands on the junction with the blade that is usually not separate from the blade; blade elliptic in various proportions, sometimes succulent (Ser. Dichotomae), margin serrate with teeth 0.5–3(–5) mm apart, often indistinct so but never truly entire, above glandless or with a pair of glands on the junction with the petiole (see there), below smooth and neither whitish nor papillate, with or without a row of strictly marginal glands, basal glands not different, secondary veins distinct, arching but mostly not joined towards the margin, smaller veins reticulate but often hardly visible. Inflorescences terminal or axillary, yellowish, simple, pistillate and staminate flowers in same thyrse, very variable in size. Bracts of staminate cymules triangular to ovate to transversely ovate, with a pair of cup- to disc-shaped glands touching the axis of the thyrse. Staminate cymules 5–13-flowered (1–3-flowered in some Neotropical species); bracteoles present, filiform. Staminate flowers with short (up to 1 mm long) pedicel only present when flowering; calyx with 2 largely fused sepals; stamens 2, filaments slightly longer than anthers. Pollen (fide Rogers, 1951) spheroidal to prolate, tricolporate or with 1 lateral pore (series Dichotomae). Pistillate flowers several (less than 15) at base of staminate thyrse, nearly sessile; calyx with 3 sepals; sepals triangular, free, glandless (absent in some Neotropical species); ovary 3-locular (2-locular in few Neotropical species), smooth; style usually short but distinct, stigmata 3 (2 in few Neotropical species), undivided, glandless. Fruits nearly sessile; 3-seeded (2-seeded in few Neotropical species), smooth, dry, dehiscing regularly along the septa in the upper part, but with a thickened, woody lower part remaining at the plant to form a (2- or) 3-lobed, woody coccophore; mericarps with persistent septae and 1 or 2 vascular strands visible on each septum. Seeds elliptic, dry, with or without caruncle.
Distribution — 30 species actually accepted, 27 of which (as well as 4 of the 5 series) strictly Neotropical, ranging from Argentina to Kansas, USA. Series Dichotomae, instead, includes 4 species in South America (dry regions of NE Brazil) and 3 in Madagascar, Mauritius, Réunion, Fiji and a few islands in Malesia: Lesser Sunda Islands, Moluccas, Philippines
Habitat & Ecology — Preferably growing under xerophytic conditions, rocky hills, open woods, scrubland, roadsides, semideserts, at least the Paleotropical species often on seashores.
Note — The species boundaries in some of the New Wold series of Stillingia are quite vague, hybridization occurs frequently, as shown by Rogers (1951) for North America. The Dichotomae, however, are still poorly known and rarely collected.
Stillingia lineata (Lam.) Müll.Arg. in DC., Prodr. 15, 2 (1866) 1157; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.v (1912) 183; Coode, Fl. Masc. 160 (1982) 86, pl. 17; Esser, Blumea 44 (1999) 194. — Sapium lineatum Lam., Encycl. 2 (1790) 734; Müll.Arg., Linnaea 32 (1863) 115. — Type: Commerson s.n. (holo P-LA, microfiche 597/1; ?iso G, L, P, P-JU), Mauritius.
Shrub to small tree, up to 12 m high. Twigs succulent, apical diameter c. 6 mm. Bark smooth, covered with leaf-scars 2.5–3 mm in diam. Stipules 0.8–1.5 by 0.3–0.75 mm, divided. Leaves alternate but apically crowded; petiole 0.3–1.7 cm long, glandless or with a pair of glands above on the junction with the blade; blade membranous and hardly to slightly succulent, orbiculate to elliptic to slightly obovate, (4–)7–24 by (3–)5–8 cm, base cuneate to obtuse, margin serrate with teeth 2–3(–4) mm apart, apex acute to rounded to retuse, above with a pair of cup-shaped glands on the junction with the petiole that sometimes are very indistinct to absent and varying even on the same twig, below with 0–17 strictly marginal glands per side, 0.5–0.75 mm long, secondary veins 16–26 pairs, distinct to indistinct, indistinctly joined towards the margin, smaller veins distinct to indistinct. Inflorescences 4–6 cm by c. 5 mm, greenish-yellow. Bracts of staminate cymules 1–2 mm long, their glands disc-shaped to flattened-cylindral glands, 1.5–3.0 by 1.25–2.5 mm, mostly along the axis and partly below the bract. Staminate cymules 5–9(–15)-flowered. Staminate flowers: pedicel 0.2–0.5 mm long; calyx c. 0.75 mm long; stamens with filaments 1 mm long when flowering, anthers c. 0.4 mm long. Pistillate flowers 5–9 per thyrse; calyx 1.5 mm long; ovary c. 4 mm long; style up to 1 mm long, stigmata 1.5 mm long. Fruits 5–6 mm long, deeply sulcate, apically retuse; pericarp c. 0.5 mm thick; remaining carpophore up to 11 mm in diameter. Seeds 5 by 4–5 mm, carunculate, brown, dotted.
Distribution — Mauritius, Réunion, Fiji and in Malesia few localities from the Lesser Sunda Islands, the Moluccas and the Philippines.
Habitat & Ecology — Often found on beaches, but also in forests up to 300 m elevation.
Note — The morphological distinction between the subspecies seems sufficiently well established (Smith, 1978; Coode, 1982). The typical subspecies from Mauritius and Réunion has firm to slightly succulent, entire leaves with hardly visible venation and no marginal glands, whereas the Malesian plants are distinguishable by thin leaves with obvious serration, venation and glands; they do not differ in generative characters. Airy Shaw (1972b) and Smith (1978) doubt the ecological distinction between the subspecies (beach vs. inland plants) proposed by Van Steenis (1966).
Stillingia lineata (Lam.) Müll.Arg. subsp. pacifica (Müll.Arg.) Steenis, Blumea Suppl. 5 (1966) 302, map 169; Airy Shaw, Kew Bull. 27 (1972) 93; Kew Bull. 37 (1982) 35; Esser, Blumea 44 (1999) 195, Fig. 6; Map 6. — Stillingia pacifica Müll.Arg. in DC., Prodr. 15, 2 (1866) 1156; Seemann, Fl. Vitiens. (1867) 232; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.v (1912) 183; Croizat, Occ. Papers Bishop Mus. 18 (1944) 71; Airy Shaw, Kew Bull. 16 (1963) 372; A.C.Sm., Allertonia 1 (1978) 397, fig. 20; Fl. Vitiens. Nov. 2 (1981) 567, fig. 151. — Type: U.S. Expl. Exped. Capt. Wilkes (holo presumably G or G-DC, n.v.; iso GH, US), Fiji, Ovalau.
Sapium plumerioides Croizat, J. Arnold Arbor. 23 (1942) 507; Salvosa, Lex. Philipp. Trees (1963) 123. — Type: Bartlett 15167 (holo A), Philippines, Babuyan Group, Dalupiri Island.
Shrub to small tree, up to 10 m high, trunk 15 cm in diameter. Leaves: blade (4–)7–24 by 3–8 cm, index (1.5–)2–4, membranous and non-succulent, margin distinctly serrate, below with 5–17 glands per side, secondary and smaller veins distinct.
Distribution — Fiji (several islands of the group) and Malesia: Lesser Sunda Islands (Sumbawa, Babar, Timor), Moluccas (Seram), Philippines (Babuyan Group).
Habitat & Ecology — In Malesia only known from coastal forest and coconut plantations on coral soil, but poorly known. On Fiji occurring along streams, on forest edges, in coastal thickets and on limestone cliffs. Altitude: 0–300 m. Flowering: on Fiji in February, July, December; fruiting: January, February, July, December.
Vernacular name — Philippines: Loi (Tagalog) (Salvosa, Lex. Philipp. Trees, 1963: 123).
Note — The type of Sapium plumerioides is a typical specimen of S. lineata subsp. pacifica. As Stillingia was not known for Malesia at this time, Croizat (1942) did not consider this genus, but compared the specimens only with Excoecaria and Sapium and therefore could not match it.
