Malesian Euphorbiaceae Descriptions

62. KOILODEPAS (Euphorbiaceae)

P.C. van Welzen. 2010. Revision of the Asian genus Koilodepas (Euphorbiaceae). Ann. Missouri Bot. Gard. 97: 218–234.

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Genus description

Key to the Malesian species

Species descriptions

Excluded Species and Specimens

Koilodepas Hassk.

    Koilodepas Hassk., Verslagen Meded. Afd. Natuurk. Kon. Akad. Wetensch. 4 (1855) 139; Bot. Zeitung (Berlin) 14 (1856) 802; Flora 40 (1857) 531 (‘Coelodepas’); Hort. bogor. descr. 1 (1858) 44 (‘Coelodepas’); Müll.Arg. in DC., Prodr. 15, 2 (1866) 759 (‘Coelodepas’); Benth. in Benth. & Hook.f., Gen. Pl. 3 (1880) 313 (‘Coelodepas’); Hook.f., Fl. Br. India. 5 (1998) 419 (‘Coelodepas’); J.J.Sm., Meded. Depart. Landb. Ned.-Indië 10 (1910) 379 (‘Coelodepas’); Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.vii (1914) 268 (‘Coelodepas’); Ridl., Fl. Malay Penins. 3 (1924) 274 (‘Coelodepas’); Pax & K.Hoffm. in Engl. & Harms, Nat. Pflanzenfam., ed. 2, 19c (1931) 124, fig. 64 (‘Coelodepas’); Croizat, J. Arnold Arb. 23 (1942) 50 (‘Coelodepas’); Airy Shaw, Kew Bull. 14 (1960) 353; Kew Bull. 16 (1963) 354; Backer & Bakh.f., Fl. Java 1 (1963) 486; W.Meijer, Bot. News Bull. Forest Dep. Sabah 7 (1967) 47; Airy Shaw, Kew Bull. 26 (1972) 284; Whitmore, Tree Fl. Malaya 2 (1973) 103; Airy Shaw, Kew Bull. Add. Ser. 4 (1975) 137; Kew Bull. Add. Ser. 8 (1980) 122; Kew Bull. 36 (1981a) 310; G.L.Webster, Ann. Missouri Bot. Gard. 81 (1944) 79; Radcl.-Sm., Gen. Euphorbiacearum (2001) 180; Welzen & Chayam. in Welzen & Chayam., Fl. Thailand 8, 2 (2007) 348; Welzen, Ann. Missouri Bot. Gard. 97 (2010) 222; G.L.Webster in Kubitzki, Fam. Gen. Vasc. Pl. 11 (2014) 136. — Conceveiba Aubl. sect. Coelodepas (Hassk.) Kuntze in T.Post & Kuntze, Lex. Gen. Phan. (1903) 138. —  Koilodepas Hassk. sect. Koilodepas: Airy Shaw, Kew Bull. 14 (1960) 383. — Type: Koilodepas bantamense Hassk.

    Calpigyne Blume, Mus. Bot. (1857) 193; Miq. Fl. Ned. Ind. 1(2) (1859) 408; Müll.Arg. in DC., Prodr. 15, 2 (1866) 1255; Boerl., Handl. Fl. Ned. Ind. 3 (1900) 244; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.vii (1914) 254; in Engl., Pflanzenr. IV.147.xiv (1919) 35. — Type: Calpigyne frutescens Blume [= Koilodepas bantamense Hassk.]

    Nephrostylus Gagnep., Bull. Soc. Bot. France 72 (Aug. 1925a) 467; in Lecomte, Fl. Indo-Chine 5 (Dec. 1925b) 327, fig. 37. — Type: Nephrostylus poilanei Gagnep. [= Koilodepas longifolium Hook.f.]

    Koilodepas Hassk. sect. Hyalodepas Airy Shaw, Kew Bull. 14 (1960) 383. — Type: K. calycinum Bedd.

Generally small trees, monoecious. Indument stellately bundled hairs and simple hairs, often dense in especially young parts and inflorescences. Stipules triangular to elliptic, late caducous, margin entire to (partly) erose to pectinate with even branching teeth, sometimes basal-marginal extrafloral nectaries, outside stellately hairy, inside simple hairs. Leaves alternate to distich along branches, simple; petiole short, usually completely pulvinate, tomentose; blade usually elliptic or oblong-elliptic, symmetric, rather coriaceous, drying greenish or brownish, base obtuse to cuneate, extreme base narrowly emarginate, margin entire to serrulate with teeth ending in small or broad glands, apex acuminate to cuspidate, upper surface smooth, generally glabrous, lower surface smooth, glabrous to hairy on veins and midrib only, extrafloral nectaries generally on the petiole connection, additional ones often nearby and often along the margin up to the apex, domatia absent; venation penninerved, slightly raised above, distinctly so beneath, nerves looped and connected near the margin, tertiary veins often scalariform, others reticulate. Inflorescences (ramiflorous, in K. bantamense and K. brevipes, to) axillary (to terminal, in K. bantamense) spikes, often several together, ± pendulous, completely staminate or lower flowers pistillate and uppers staminate, latter braking off; staminate flowers in dense clusters of generally 10 or more flowers per node, pistillate flowers solitary per node (or with a few staminate ones); rachis tomentose. Flowers actinomorphic; bacts present, and especially with the pistillate flowers also bracteoles, both with an often erose margin, outside stellate hairs and inside simple ones, basally outside often extrafloral nectaries; petals and disc absent. Staminate flowers small; pedicel very short, widening apically, with few hairs; calyx generally 2–4-lobed, lobes valvate, stellately hairy outside, simple ones inside; stamens glabrous, united on a short and apically broadening androphore, 4–8, in a circle, filaments either thread-like (K. laevigatum) and anthers with parallel thecae or filamens sulcate in lower 2/3^rd and narrowing apically with thecae divergent, ^-shaped, anthers subapically dorsifixed, opening intrors with short longitudinal slits; pistillode absent to short, protruding from centre of androphore. Pistillate flowers much larger than staminate ones; pedicel short, broadening towards apex, hairy, often elongating considerably in fruit; sepals or calyx lobes imbricate, persistent, either lobes free and triangular to basally or almost completely united, calyx up to c. 10-lobed, either leaving ovary free to covering it completely and tightly (calyx seemingly absent), in some species calyx enlarging in fruit and covering fruit, stellately hairy outside, simple hairs inside; ovary (2)3(4)-locular, villose, 1 ovule per locule; style absent to present, stigmas apically several times bifid (stigmas individually identifiable) to multifid and fan-like (individual stigmas not visible), on upper surface long, branching papillae, beneath tomentose. Fruits lobed rhegmas (capsules), dehiscing completely septicidally and partly (from above) loculicidally, outside tomentose (somewhat scurfy), inside basally a few stellate hairs; wall woody; columella very sturdy, broadly obtriangular with large remnants of the septa. Seeds obovoid, somewhat flattened and keeled on the inside, smooth, shining, often somewhat marbled, hilum triangular, caruncle absent; endosperm fleshy; cotyledons broad, flat.

    Distribution — Nine species, one in India, one from S. China to central Thailand, two widespread from Thailand to Borneo and Sumatra (one extending to Java), one in New Guinea, all others mainly endemics of Borneo.

    Notes — 1. Hasskarl (1855, 1856) first used the Greek version of the genus name, Koilodepas, which he later changed (1857, 1858) to a more Latinised form, Coelodepas. Koilodepas is the older variant and, therefore, used in this revision. Croizat (1942) indicated that a proposal was submitted to conserve the variant Coelodepas, because it was used by most (older) authors. This proposal was rejected.

2. Croizat (1942) also indicated that the type of the genus (K. bantamense) is a nomen nudum. This is untrue, because Hasskarl published a monotypic genus and then the Inernational Code of Botanical Nomenclature allows the generic description to be the specific description as well.

1. Koilodepas bantamense Hassk.

    Koilodepas bantamense Hassk., Verslagen Meded. Afd. Natuurk. Kon. Akad. Wetensch. 4 (1855) 140; Bot. Zeitung (Berlin) 14 (1856) 802; Flora 40 (1857) 532 (‘Coelodepas’); Hort. bogor. descr. 1 (1858) 45 (‘Coelodepas’); Miq., Fl. Ned. Ind. 1(2) (1859) 398 (‘Coelodepas’); Müll.Arg. in DC., Prodr. 15, 2 (1866) 759 (‘Coelodepas’); J.J.Sm., Meded. Depart. Landb. Ned.-Indië 10 (1910) 380 (‘Coelodepas’); S.Moore, J. Bot. 63, Suppl. (1925) 101 (‘Coelodepas’); Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.vii (1914) 269, fig. 42a–c; Airy Shaw, Kew Bull. 14 (1960) 384; Backer & Bakh.f., Fl. Java 1 (1963) 486; Airy Shaw, Kew Bull. 36 (1981a) 311; Welzen, Ann. Missouri Bot. Gard. 97 (2010) 224, Fig. 1a, b, 2e, g. — Type: Hasskarl s.n., barcode L  0016250 (L holo), Java, originally collected in Bantam, later cultivated in Bogor Botanical Garden.

    Calpigyne frutescens Blume, Mus. Bot. 2 (1857) 193; Miq., Fl. Ned. Ind. 1(2) (1859) 408; Müll.Arg. in DC., Prodr. 15, 2 (1866) 1255; Boerl., Handl. Fl. Ned. Ind. 3 (1900) 244; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.vii (1914) 255. — Ptychopyxis frutescens (Blume) Croizat, J. Arnold Arb. 23 (1942) 49. — Koilodepas frutescens (Blume) Airy Shaw, Kew Bull. 14 (1960) 385; Kew Bull. Add. Ser. 4 (1975) 138. — Lectotype (designated by Croizat, 1942): Korthals s.n., s.d., barcode L  0016252 (holo L, photo A), Borneo, G. Pamatton. See note 2 and 3.

    Koilodepas wallichianum Benth., Hooker’s Icon. Pl. 13 (1879) t. 1288 (‘Coelodepas’); Hook.f., Fl. Br. India 5 (1887) 419 (‘Coelodepas’); Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.vii (1914) 269 (‘Coelodepas’); Ridl., Fl. Malay Penins. 3 (1924) 275 (‘Coelodepas’); Airy Shaw, Kew Bull. 14 (1960) 387; Kew Bull. 16 (1963) 354, p.p., pro Bentham; Whitmore, Tree Fl. Malaya 2 (1972) 104. — Type: G. Porter in Herb. Wallich 9098 (holo K-WALL, n.v.; iso K), Malay Peninsula, Penang Hills. See note 1.

    Koilodepas ferrugineum Hook.f., Fl. Br. India 5 (1887) 420; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.vii (1914) 269 (‘Coelodepas’); Ridl., Fl. Malay Penins. 3 (1924) 274 (‘Coelodepas’); Airy Shaw, Kew Bull. 14 (1960) 385; Whitmore, Tree Fl. Malaya 2 (1973) 104. — Type: W. Griffith KD 5017 (K holo; iso L, s.n., L  0016235), Malacca.

    Koilodepas cf. stenosepalum auct. non Airy Shaw: Airy Shaw, Kew Bull. 16 (1963) 356, p.p., excl. type: S (Pickles) 3451; S (Pickles) 3621

Shrubs to trees up to 27 m high, d.b.h. up to 50 cm, sometimes rheophytic when young; flowering branches 1.5–4 mm in diameter. Outer bark smooth, white to patchy grey and grey-green to grey-brown to honey-coloured, papery, sometimes flaking, soft; inner bark pink to reddish brown to brown, thin, brittle-fibrous; wood medium hard, sapwood cream to yellow, heartwood yellow to orange. Stipules triangular, 2–8 by 0.6–1.5 mm, margin often somewhat erose or with at most one or two upright teeth, mainly on one side.  Leaves: petiole 3–16 mm long, round to flattened above; blade ovate-oblong to elliptic-oblong, 5.8–33 by 1.7–11.2 cm, length/width ratio 2.7–5.3, drying (greenish to) brownish, base truncate to cuneate, margin coarsely serrulate (to entire), flat to slightly recurved, teeth ending in a glandular region; apex acute to cuspidate; upper surface dull dark green; lower surface dull green, glabrous to hairy on basal part of the midrib, nerves 11–15 per side, often somewhat bullate between nerves. Inflorescences up to 10.5 cm long, yellowish green to pale brown. Flowers whitish in bud to grey-yellow when dehisced. Staminate flowers 1.2–2.4 mm in diameter; bracts triangular, 1.1–2.2 by 1.1–3.5 mm, sometimes margin with teeth, at base often with extrafloral nectaries; pedicels 0.2–0.9 mm long; calyx 1–1.2 mm high, 3- or 4-lobed, lobes triangular, 0.7–1.2 by 0.8–1.4 mm; stamens 4 or 5, androphore 0.7–0.8 mm high, filaments 0.7–1 mm long, sulcate, anthers 0.2–0.3 by 0.3–0.5 mm, yellow; pistillode absent to c. 0.2 mm long. Pistillate flowers 2.5–3.5 mm in diameter; bracts triangular, 2–7 by 1.2–2.3 mm, margin often with round extrafloral nectaries, often united with the bracteoles; bracteoles similar, much smaller, 1.8–2.5 by 0.6–1.8 mm; pedicel 0.7–1.8(–22 in fruit) mm; calyx tightly urceolate and adnate to ovary, 2–3.3 mm high, 7- or 8-lobed, lobes inconspicuous, outside usually extrafloral nectaries on tube, splitting into (horizontal to) reflexed lobes, in fruit not much increasing in size, up to 3(–5) mm long; ovary 3-locular, 2–3 by 1.5–2.7 mm, style 0–0.3 mm long, stigmas 1.5–2.5 mm long, yellow, deeply bilobed, each lobe split several times, spreading fan-like, very compact, individual stigmas not visible. Fruits lobed rhegmas, 16–18 by 8–11 mm, yellowish green when young, to orange, brown hairy; wall c. 1.2 mm thick; columella 6–10 by 4.5–7.3 mm. Seeds 7–8.5 by 7.2–9 by 6–8.2 mm.

    Distribution — Thailand (South-western and Peninsular part), Malesia: Malay Peninsula, Sumatra, Java, Borneo.

    Habitat & Ecology — Primary dry evergreen forest (Thailand) and primary rain foreset, sometimes also secondary forest, scrubs and overgrown rubber plantations; soil yellow-red loam; bedrock granite or sandstone. Altitude: 50–400 m. Flowering: January to August; fruiting: May and June, October and November.

    Vernacular names — Sumatra: Kayoe toelan (Lampung Prov.). Borneo (Sarawak): Luti (Kayan).

    Uses — The wood is used for wood carving, knife handles and sheaths.

    Notes — 1. This is a variable species and unfortunately very much alike K. longifolium and K. hainanense. All three species have generally elliptic-oblong leaves with an entire up to coarsely serrulate margin. Specimens formerly stored under K. bantamense, K. ferrugineum, K. frutescens, K. wallichianum and partly under K. longifolium have pistillate flowers with a narroly urceolate calyx (with or without glands), which do not enlarge in fruit (one specimen somewhat exceptional). The stigmas are short and branch into broad fans. The stipules generally have an entire margin or have one or two teeth. Koilodepas hainanense (incl. Nephrostylus poilane) differs in the pistillate flowers with calyces that enlarge in fruit, in flower the calyces are not narrowly enclosing the ovary, but somewhat folded around the ovary; the stipules also show more teeth. The calyx of the pistillate flowers of Koilodepas longifolium (incl. K. glanduliferum and K. subcordatum) reaches till halfway the ovary and slightly enlarges in fruit, the stigmas are less branched and generally have a longer unbranched basal part; the stipules usually have upwards bent teeth. Koilodepas hainanense only slightly overlaps in SW Thailand with K. bantamense. However, the other two species largely overlap in distribution. Luckily, there is one more chacarter that generally separates the two species, K. longifolium has very small glands on the marginal teeth of the leaf blade, while K. bantamense generally has glands that broadly cover the rounded apex of the teeth. The material known as K. ferrugineum has (dried!) a very dark brown indumentum and the specimen (type only) tends to be hairy. The specimens referred to Koilodepas wallichianum have relatively large leaves with a truncate base of the blade. This is the only differing character and because the same variability is found in K. longifolium, the name K. wallichianum is treated as a synonym. Funny is that both K. bantamense and K. longifolium often have witch brooms in the inflorescences, but both develop differently. In K. bantamense especially the bracts, bracteoles and calices are enlarged, with only a several bracts within the calices, while in K. longifolium the bracts and bracteoles are normal, the calices are slender and on relatively long pedicels, but inside each calyx there is a far extending spike-like structures only consisting of bracts.

2. The names K. bantamense and K. frutescens were always treated as separate species, mainly because different persons revised different islands (Java: Backer & Bakhuizen van den Brink f., 1963 and Sumatra and Borneo: Airy Shaw, 1981 and 1975, respectively) or revised island by island and did not see the resemblance between both piles of specimens. Typical are the strongly urceolate pistillate calyx, which sticks to the young ovary (falling off when the fruit develops), the hardly serrate leaves (especially in the lower half), the short stipules, and the low number of stamens.

2. Blume (1857) did not indicate the specimens he used, only that they were from Sulawesi (Celebes) and Borneo. According to Miquel (1859), the Sulawesi collections were made by Forsten and the Borneo ones by Korthals. However, the Sulawesi specimens could not be retraced. Therefore, Croizat (1942) selected a Korthals specimen from the material present in L as lectotype.

3. Croizat (1942) indicated that his combination was a nomum novum (and it was subsequently treated as a new name by Airy Shaw, 1960, 1975). However, Croizat clearly referred to Blume’s name (1857) as the basionym, thus it is not a new name but a new combination.

4. Note Airy Shaw (1981a): Lörzing 16329 referable to this species, with ‘witches’ broom’ inflorescences due to mite attack.

2. Koilodepas brevipes Merr.

    Koilodepas brevipes Merr., Philipp. J. Sc. 30 (1926) 80 (‘Coelodepas’); Pl. Elmer. Born. (1929) 156; Airy Shaw, Kew Bull. 14 (1960) 389; W.Meijer, Bot. News Bull. Forest Dep. Sabah 7 (1967) 47; Airy Shaw, Kew Bull. Add. Ser. 4 (1975) 138; Welzen, Ann. Missouri Bot. Gard. 97 (2010) 225, Fig. 1f, g. — Koilodepas brevipes Merr. var. brevipes: Airy Shaw, Kew Bull. Add. Ser. 4 (1975) 138. — Type: D.D. Wood 1291 (iso K), British North Borneo, Kalumpang.

    Koilodepas stenopetalum Airy Shaw, Kew Bull. 14 (1960) 390, p.p, type only; W.Meijer, Bot. News Bull. Forest Dep. Sabah 7 (1967) 47. — Koilodepas brevipes Merr. var. stenosepalum (Airy Shaw) Airy Shaw, Kew Bull. Add. Ser. 4 (1975) 138. — Type: L.L. Forman 442 (K, holo, n.v.; iso L), Indonesian Borneo, Gunung Sahara, Belajan River (see note 1).

    Koilodepas stenosepalum auct. non Airy Shaw: Airy Shaw, Kew Bull. 14 (1960) 390, p.p., exl. type; Kew Bull. 16 (1963) 356.

Undershrubs to small trees, up to 10 m high, d.b.h. up to 20 cm; flowering branches 2-3 mm in diameter. Outer bark smooth, white to light brown; inner white to pale grey; sapwood white to yellowish, hard. Stipules triangular 3.7–10 by 0.7–1.2 mm, margin often erose, basally generally a round, black, shiny gland on one side. Leaves: petiole 3–7 mm long, round to channelled above; blade (somewhat ovate to) elliptic to oblong, 8–32.5 by 2–11 cm, length/width ratio 2.7–5, drying brownish, base truncate to rounded (to cuneate), poculiform (convex), margin coarsely serrulate with glandular teeth, strongly recurved at base; apex caudate, mucronate, lower surface subglabrous to somewhat hairy on venation, nerves 13–15 per side, somewhat bullate between the nerves. Inflorescences up to 10.5 cm long, greenish brown. Staminate flowers 1.3–1.7 mm in diameter, green to pale white-yellow to yellow to yellowish grey to white, fragrant with smell of lemon; bracts triangular, 0.6–2.2 by 1–2.2 mm, margin often with teeth, at base with round, shiny extrafloral nectariesn; pedicels 0.3–0.8 mm long; calyx 1.3–2.2 mm high, with 3 or 4 lobes, latter 0.6–1 by 0.7–1 mm; stamens 6–8, androphore 0.6–1.5 mm long, filaments 0.7–0.9 mm long, sulcate, anthers c. 0.3 by 0.3–0.4 mm; pistillode 0.3–0.7 mm long. Pistillate flowers c. 2.2 mm in diameter; bracts triangular 2–3.5 by 1–2 mm, margin serrate, basally with glands; bracteoles like bracts, smaller, 1–1.5 by 0.3–0.5 mm; pedicel c. 0.3 mm long, lengthening in fruit up to 16 mm; calyx with 6, 8 or 10 free to basally connate lobes, latter triangular, 1.5–1.8 by 0.7–0.8 mm when young, extending in fruit up to 12 by 2 mm, basally and often halfway along margin with round, shiny extrafloral nectaries, not well visible when young, distinct in fruit; ovary 3(4)-locular, 1.8–2 by 1–1.3 mm, style 1–3 mm long, stigma 1.8–3 mm long, top split twice to several times, usually with 2 or 3 main lobes, stigmas individually visible. Fruits lobed rhegmas, 14–18 by 8–11 mm, red to reddish black to golden brown; wall c. 0.8 mm thick; columella 7–8 by 8–9 mm. Seeds c. 7 by 6.5–6.8 by 6–6.5 mm.

    Distribution — Malesia: Borneo (endemic).

    Habitat & Ecology — Primary forest (in tact or recently logged) or disturbed forest, on flat to undulating terrain or ridges and along roadsides; soil dark red-brow to yellowish black, sandy loam or sandstone. Altitude: Sea level up to 330 m. Flowering: January, March, April, July, August to November; fruiting: March?, August, October, December.

    Vernacular names — Borneo: Sabah: Ulas (Malay or Suluk); Kalimantan Timur: Kaju gading.

    Notes — 1. We could not really detect a difference between both varieties. The calyx lobes of the pistillate flower are short in flower and become long and slender in fruit. There seems to be no difference between both varieties (var. stenosepalum should have longer, more slender sepals) other then the basal connection between the sepals, present in var. brevipes, less distinct in var. stenopetalum. Further differences could not be found (at first it seemed that only the sepals of var. stenopetalum had extrafloral nectaries, but these are usually always present, though indistinct in flower). Therefore, both varieties are united. The most typical character for K. brevipes is the poculiform base of the leaf blade; also typical are the pistillate sepals, almost free and extending in length in fruit.

2. Amdjah 365, Forman 442, Kostermans 10326, and 13949 have galls on the lower surface of some leaves, which are about 4 mm in diameter and vulcano-like.

3. Koilodepas cordisepalum Muzzazinah ex Welzen

    Koilodepas cordisepalum Muzzaz. & Welzen in Welzen, Ann. Missouri Bot. Gard. 97 (2010) 227. — Type: De Wilde & De Wilde-Duyfjes 20339 (holo L), Indonesia, Sumatra, Atjeh Province, Middle Alas River (Lae Sauraya) area, c. 15 km N of Gelombang, S. of Bengkong River.

     Koilodepas hainanense auct. non (Merr.) Croizat (‘Coelodepas’): Airy Shaw, Kew Bull. 14 (1960) 384; Kew Bull. 36 (1981a) 311.

Shrubs to trees, up to 12 m high, d.b.h. up to 30 cm. Stipules triangular, 2.5–5.5 by 0.7–1 mm, margin slightly erose, basally generally a round, black, shiny gland on one side. Leaves: petiole 2–9 mm long, round; blade ovate to elliptic to oblong, 8.5–22 by 2.4–10 cm, length/width ratio 2.2–3.5, drying greenish, base rounded, flat, margin coarsely serrulate with glandular teeth, somewhat recurved, apex caudate, lower surface slightly hairy on midrib, nerves 10–13 per side, slightly bullate between the nerves. Inflorescences up to 10 cm long, hairy, pale grey-green to pale creamy brownish. Flowers fragrant. Staminate flowers 1.1–1.5 mm in diameter, (dirty) creamy; bracts triangular, c. 2.2 by 1.5–2.2 mm, margin entire, at base with a round, shiny extrafloral nectary, bracteoles not seen; pedicels 0.3–0.7 mm longs; calyx 1.3–2 mm high, with 3 or 4 lobes, latter 0.4–0.8 by 0.8–1 mm; stamens 5–7, androphore 0.7–1.5 mm long, filaments 0.4–1 mm long, sulcate, anthers c. 0.3 by 0.6–0.7 mm, yellow; pistillode 0.8–1 mm long, 1- or 2-lobed. Pistillate flowers 3.6–3.7 mm in diameter, greenish-creamy; bracts triangular, 2–3.3 by 0.6--2 mm, margin entire, basally with 1 or 2 glands; bracteoles smaller, 1.2–1.3 by 0.3–1 mm; pedicel 0.8–1 mm long, lengthening in fruit up to 5 mm; calyx basally united, up to 3.2 mm high (enlarging in fruit to c. 18 mm high), lobes 6, triangular, 2.3–2.8 by 1–1.5 (enlarging in fruit to c. 8 by 8 mm), extrafloral nectaries absent; ovary 3-locular, c. 1.5 by 1 mm, style 0.8–1.6 mm long, stigma 4–5.5 mm long, pale (greenish) yellow to pale purplish, top split into two major branches, each with 3 lobes, stigmas individually visible. Fruits lobed rhegmas, only young one seen, c. 10 by 6 mm, dull brownish green or yellowish green; wall c. 0.8 mm thick; columella c. 6 by 4–4.5 mm. Seeds c. 6 by 6 by 5.3 mm.

    Distribution — Endemic in Sumatra (Prov. Aceh, Gunung Leuser Nature Reserve).

    Habitat & Ecology — (Logged) primary hill forest and riverine forest, on shaded slopes and/or along rivulets; soil alluvial or yellow red loamy (rich in lime) soil on a sandstone plateau, shaded slope, near rivulet. Altitude 40–400 m. Flowering: July, August; fruiting: May, July.

    Note — Airy Shaw (1960) already indicated that material from Sumatra (de Wilde & de Wilde-Duyfjes 12463) might be a new species, but due to lack of sufficient material, he referred the specimen to K. cf. hainanense because of the enlarging pistillate sepals and green colour of the dry material. However, the type of K. hainanense (W.Y. Chun 1092, A) has a brownish colour and the pistillate flowers have much shorter stigmas (up to 3.2 mm long). Thus, the specimens from Sumatra are indeed an identifiable new species.

4. Koilodepas homaliifolium Airy Shaw

    Koilodepas homaliifolium Airy Shaw, Kew Bull. 36 (1981b) 609; Welzen, Ann. Missouri Bot. Gard. 97 (2010) 230, Fig. 1c, i. — Koilodepas sp. nov.?: Airy Shaw, Kew Bull. Add. Ser. 8 (1980) 122. — Type: Streimann & Kairo LAE 51550 (K, holo, n.v.; iso L), Kuriva Forestry Area, near veimauri River, Port Moresby sub-district,Central district, Territory of New Guinea.

Trees, up to 24 m high, bole up to 18 m high, straight, d.b.h. up to 38 cm; crown spreading; flowering twigs c. 3 mm in diameter. Outer bark brown to dark grey, papery, flaky; middle and inner bark red, layered; wood very hard and heavy, sapwood straw-coloured, heartwood yellowish straw. Stipules oblong-ovate, 4.3–9 by 1–1.5 mm, margin entire but apically sometimes erose. Leaves: young flush drying reddish; petiole 3–8 mm long, channelled above; blade elliptic-oblong, 10.5–23 by 4.1–8.3 cm, length/width ratio 2.6–3.3, drying brownish, base emarginate to broadly cuneate, margin laxly serrulate, teeth rounded, glandular; apex acute to acuminate, upper surface dark green, lower surface somewhat hairy when young, especically venation, green, nerves 11–15 per side. Inflorescences up to 16 cm long. Flowers grey to yellow. Staminate flowers c. 1 mm in diameter; bracts triangular, c. 1.8 by 1.8 mm, margin entire?, extrafloral nectaries not seen; pedicel at most c. 0.3 mm long; calyx 3-lobed, lobes almost completely free, elliptic, c. 1 by 0.7 mm, apex rounded; stamens 4, androphore c. 0.3 mm high, filaments 0.5–0.7 mm long, sulcate, anthers c. 0.3 by 0.5 mm; pistillode present. Pistillate flowers c. 4.2 mm in diameter, sessile; bracts triangular, c. 2.5 by 0.8 mm; bracteoles minute; calyx 6-lobed, c. 2.1 mm high, lobes acute; ovary 3-locular, c. 2 by 1.5 mm; style c. 0.5 mm long, stigmas c. 2.5 mm long, apex multifid, individual stigmas visible. Fruits and seeds unknown.

    Distribution.— Endemic in Papua New Guinea (Central Province).

   Habitat & Ecology.— Understorey of lowland rain forest. Altitude: c. 70 m. Flowering: February, May.

5. Koilodepas laevigatum Airy Shaw

    Koilodepas laevigatum Airy Shaw [ex W.Meijer, Bot. News Bull. Forest Dep. Sabah 7 (1967) 47, nom. nud.], Kew Bull. 23 (1969) 83; Kew Bull. Add. Ser. 4 (1975) 13; Welzen, Ann. Missouri Bot. Gard. 97 (2010) 230, Fig. 2b, c, h. — Type: S (Sibat ak Luang) 21928 (K holo, n.v.; iso L), Sarawak, 4^th Division, Bukit Mersing, Anap.

    Aporosa brevipetiolata Merr. ex H.G.Keith, North Borneo Forest Rec. 2 (1938) 48, 79, 125, nom. nud.; North Borneo Forest Rec. 2, ed. 2 (1952) 116, 192, 292, nom. nud. — Representative specimens: D.D. Wood 2254 (holo K), British North Borneo [= Sabah].

    Koilodepas longifolium Hook.f. var. integrifolium Airy Shaw, Kew Bull. 14 (1960) 388; Kew Bull. 16 (1963) 355. — Type: P. Orolfo 1821 (holo K; iso L as P. Keeper 1821), British North Borneo [= Sabah], Bengkoka Kadas (according to Airy Shaw, 1960, collected on 27 April 1923, but this is 27 April 1932).

(Small) trees, up to 13 m high, bole up to 5 m high and up to , straight, d.b.h. up to 14 cm; flowering branches 2–3 mm thick. Outer bark smooth to much grooved to flaky, greyish or greyish white to white-brown, thin or papery; inner bark pale green to orange-yellow to reddish to ochre, hard; sapwood pale white to yellowish orange. Stipules triangular 2–4 by 1–1.7 mm, margin erose, late caducous, marginal basal glands absent. Leaves: petiole 6–11 mm long, channelled abovee; blade (ovate to) elliptic to oblong, 13.5–34 by 3–13 cm, length/width ratio 3.3–4.5, drying greenish, base broadly cuneate, margin irregularly entire, seldom apically one or a few teeth, flat, apex acuminate to cuspidate, lower surface glabrous, nerves c. 12 per side. Inflorescences up to 7 cm long. Staminate flowers 1–1.3 mm in diameter (excluding stamens), pale greenish to whitish to pale yellow; bracts ovate, c. 2 by 1.6 mm, margin slightly erose, basal marginal gland on one side; pedicels c. 0.3 mm long; calyx 1.2–1.4 mm high, glabrous, with 2 or 4 lobes, latter triangular c. 0.6 by 0.6–1.2 mm; stamens 4 or 5, androphore c. 0.9 mm long, filaments thread-like, 1.3–2.4 mm long, white, anthers ovate, c. 0.4 by 0.2–0.3 mm, thecae parallel, green; pistillode c. 0.3 mm long. Pistillate flowers c. 2 mm in diameter (excluding stigma), green to yellowish white to white; bracts ovate, 2.3–2.5 by 2–2.3 mm, margin erose; bracteoles triangular, 1.7–1.8 by 0.7–0.8 mm, like bracts; pedicel c. 2 mm long, extending to 12 mm in fruit; calyx with 8–12 lobes, basally connate, lobes triangular, 0.7–2 by 0.5–1.7 mm, usually glands on united part and on lobe apices; ovary c. 2.3 by 3 mm, 3-locular, light green with orchrish brown hairs to pink, style 0.5–1 mm long, stigmas 3.3–6 mm long, lower half folded, upper half deeply bilobed, stigmas individually visible. Fruits lobed rhegmas, 15–18 by 10–11 mm, pale grey and white (immature) to pale yellowish; calyx ± recurved; wall c. 1.5 mm thick; columella 9–10 by 8–9 mm. Seeds 8–10 by 8–10 by 6.5–8.7 mm.

    Distribution — Borneo(Sabah, Sarawak, Kalimantan Timur).

    Habitat & Ecology — Primary dipterocarp forest, secondary forest, generally on hills; soil sandy, sandstone and shale, basalt, conglomerated clay-stone and sandstone. Altitude: sea level up to 750 m. Flowering: February to May, August to October; fruiting: May, August.

    Vernacular names — Sabah: Akar, Kilas (Malay); Pilas (kayu) (Kedayan) (Keith, 1938, 1952). Shaw 1960: Puti (? pati) (Dusun Rongos); kilas (Bajau Lobok); rongrongkoi (Malay); kelis-kelis (Dusun Kinabatangan). Sarawak: Puti (Iban)

6. Koilodepas longifolium Hook.f.

    Koilodepas longifolium Hook.f., Fl. Br. India 5 (1887) 420 (‘Coelodepas ? longifolium’); Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.vii (1914) 270 (‘Coelodepas’); Ridl., Fl. Malay Penins. 3 (1924) 275 (‘Coelodepas’); Airy Shaw, Kew Bull. 14 (1960) 388; Kew Bull. 26 (1972) 284; W.Meijer, Bot. News Bull. Forest Dep. Sabah 7 (1967) 47; Airy Shaw, Kew Bull. 26 (1972) 284; Whitmore, Tree Fl. Malaya 2 (1973) 104; Airy Shaw, Kew Bull. Add. Ser. 4 (1975) 139; Kew Bull. 36 (1981a) 311; Radcl.-Sm., Gen. Euph. (2001) 180, fig. 22; Welzen & Chayam. in Welzen & Chayam., Fl. Thailand 8, 2 (2007) 349, Fig. 12; Welzen, Ann. Missouri Bot. Gard. 97 (2010) 231, Fig. 1d, h, 2a, 3a-f. — Koilodepas longifolium Hook.f. var. longifolium: Airy Shaw, Kew Bull. 14 (1960) 388. — Type: King’s collector 6502 (holo K), Malaysia, Perak, Larut.

    Koilodepas glanduligerum Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.vii (1914) 270, fig. 42d (‘Coelodepas’); Ridl., Fl. Malay Penins. 3 (1924) 275 (‘Coelodepas’); Airy Shaw, Kew Bull. 16 (1963) 354. — Lectotype (selected here): Ridley 6481 (holo K; iso L), Singapore, Garden Jungle. See note 1.

    Koilodepas subcordatum Gage, Rec. Bot. Surv. India 9 (1922) 239, p.p., pro Curtis 1271 (‘Coelodepas subcordatus’). — Lectotype (indirectly by Airy Shaw, 1960, other syntype K. longifolium): Curtis 1271 (K, n.v.), Malay Peninsula, Penang, Bukit Penara. Paratype: Curtis 1374 (K), Pangkore.

Small trees up to 12 m high, bole up to 18 cm thick; flowering branches 1.5–2.3 mm in diameter. Outer bark white to light brown, smooth, slightly papery; inner bark pink, thin; wood yellow. Stipules triangular, 3.7–8 by 1–1.2 mm, late caducous, margin (entire to somewhat erose or) with several upright teeth, basal glands absent. Leaves: petiole 3–20 mm long, round; blade elliptic to elliptic-oblong, 8.5–27 by 2.7–8.2 cm, length/width ratio 3.1–3.2, drying brownish, base rounded to cuneate, margin (entire to) coarsely serrulate, flat to slightly recurved, teeth ending in a small and narrow gland, apex acuminate to cuspidate, sometimes mucronulate, upper surface mid green to very dark green, shiny; lower surface glabrous to hairy along midrib and basal nerves (Borneo), (slightly) paler green, nerves 9–15 per side, sometimes somewhat bullate between nerves. Inflorescences up to 12 cm long, dark yellow, witch brooms sometimes present, dark brown hairy, branching, flowers consisting of calyx cups, each with a short spike of bracts in it. Flowers pale green with a silvery tinge to cream to yellow. Staminate flowers 0.8–1.3 mm in diameter; bracts broadly ovate, 0.7–1.8 by 1–2 mm wide, sometimes split or margin erose, the basal part of the margin sometimes with round extrafloral nectaries; pedicels 0.2–0.8 mm long; calyx with 3 or 4 lobes, lobes entire or bilobed, sometimes split and seemingly 3 or 4 sepals, 0.9–1.2 mm high, teeth triangular, 0.5–0.6 by 0.4–0.8 mm, all acute; stamens 4 or 5 (or 6), androphore 0.2–0.4 mm high, filaments 0.5–0.6 mm long, sulcate, anthers c. 0.3 by 0.4 mm; pistillode absent to 0.4 mm long. Pistillate flowers 1.7–3 mm in diameter; bracts triangular 2.5–4.7 by 0.7–1 mm, sometimes glandular, margin often erose; bracteoles similar, 1.2–2.5 by 0.4–0.9 mm; pedicel 0.8–2.3(–11 in fruit) mm; calyx till halfway ovary, 0.6–2 mm high, 6–12-lobed, lobes triangular, 0.6–1 by 0.4–0.8 mm, outside usually extrafloral nectaries on tube; ovary (2)3-locular, 1.7–2 by 1.8–2 mm, style 0–0.8 mm long, stigmas 1.5–2.1 mm long, deeply bilobed till upper 1–2.2 mm, each lobe split somewhat, stigmas individually visible. Fruits lobed rhegmas, 12–14 by 8.5–10 mm, dark yellow to brownish; wall 0.8–1 mm thick; calyx reflexed, not increasing in size; columella broadly obtriangular, 6–6.5 by 4–6 mm long, basally few caducous stellate hairs. Seeds 6.5–7 by 7.5–7 by 5.2–6 mm.

    Distribution— S. Thailand (Yala), Malay Peninsula (incl. Singapore), Sumatra (Riau Prov., Bangka Island), Borneo (Sabah, Brunei, Sarawak).

    Habitat & Ecology— Primary mixed lowland dipterocarp forest and kerangas forest; soil: Sandstone, diorite scree, granitic sand, sandy clay, clay loam. Altitude: 6–330 m. Flowering: January to October, December; fruiting: January, June, July, September. Small black ants in “earth” nests among fruits.

    Vernacular names— Peninsular Malaysia: Semantum. Borneo: Sabah: Kilas (Brunei Benuni); Sarawak: Bantas (Iban).

    Notes — 1. The selected lectotype (Ridley 6481) was selected from three specimens, one was not seen (Ridley s.n., Malay Peninsula, Bukit Timah) and the other, Ridley 4426 (K) is K. bantamense.

2. The specimen KL (Teo & Pachiappan) 2659 is presumably a non-flowering water shoot with very large leaves (up to 32 by 8 cm) and no other character then the small glands in the marginal leaf blade teeth permit the conditional identification as K. longifolium.

3. For the differences between K. bantamense, K. hainanense and K. longifolium see note 1 under K. bantamense.

7. Koilodepas pectinatum Airy Shaw

    Koilodepas pectinatum Airy Shaw, Kew Bull. 23 (1969) 82; Kew Bull. Add. Ser. 4 (1975) 139; Welzen, Ann. Missouri Bot. Gard. 97 (2010) 232, Fig. 1e, 2f. — Type: SAN (Sinanggul) 39941 (K holo, n.v.; iso L), Sabah, Lahad Datu Distr., Kennedy Bay, Silabukan Forest Reserve, Block 62.

(Shrubs to) small trees, up to 17 m high, bole up to 11 cm high, d.b.h. up to 8 cm, girth 45 cm; flowering branches 2–3.5 mm in diameter. Outer bark smooth, whitish to greyto black, papery; inner bark pale yellowish to yellowish red to red to brownish; sapwood white to yellowish to orange-yellow, medium hard. Stipules oblong-ovate, 10–13 by 1.5–3 mm (excluding teeth), pectinate with up to 6 mm long teeth, perpendicular to main part, teeth with secondary perpendicular teeth. Leaves: petiole 3–15 mm long, round to reniform near blade; blade oblong, 7–28 by 2.4–10.7 cm, length/width ratio 2.6–3.8, drying brownish, base rounded, margin serrulate with glandular teeth, apex acuminate to caudate, lower surface subglabrous to rather hairy, most often on venation, nerves 10–14 per side, often bullate between nerves. Inflorescences up to 12.5 cm long, hairy, pale green. Flowers white to yellowish green to reddish to brownish. Staminate flowers c. 1 mm in diameter; bracts ovate to triangular, 1.7–2 by 1.5–1.8 mm, at base sometimes with small bracteoles or extrafloral nectaries, margin with raised glands; pedicel c.0.3–0.8 mm long; calyx 3-lobed, lobes easily detaching, c. 1 mm high; stamens 4, androphore 0.2–0.4 mm high, filaments c. 0.7 mm high, sulcate, anthers c. 0.3 by 0.5 mm; pistillode absent. Pistillate flowers: bracts ovate to triangular, c. 5 by 2.5 mm, margin with raised glands; bracteoles similar, c. 3 by 2 mm; sepals (6–)10, free, ovate, 3–3.3 by 1.2–1.3 mm, enlarged in fruit up to c. 3 by 1.5 cm, purple, margin with raised glands; ovary 3-locular, style 1–3 mm long, stigmas 2.7–3 mm long, deeply bifid, apices multifid, yellow, fan-like, individual stigmas not visible. Fruits rhegmas, 1.3–2 by 1.1–1.3 cm, greenish to brownish; columella c. 9 mm long. Seeds obovoid, 8–10 by 8–9 by 7–7.5 mm.

    Distribution— Malesia: Malay Peninsula (one specimen: Stone & Sidek 12616), Borneo (Sabah, NE Kalimantan).

    Habitat & Ecology— Primary lowland dipterocarp forest, secondary forest, logged-over forest, open areas along logging roads, along rivers; soil occasionally limestone. Altitude: 50–850 m. Flowering: March, April, June to October, December; fruiting: February, March, July to December.

EXCLUDED SPECIES AND SPECIMENS

    Koilodepas hosei Merr., Philipp. J. Sc. Bot. 11 (1916) 66 (‘Coelodepas’). — Type: Hose 465 (holo K, n.v.; iso L),Sarawak, Baram district, Entoyut River. = Claoxylon hosei (Merr.) Airy Shaw, Kew Bull. 20 (1966) 402.

    Koilodepas sp.: Merr., Pl. Elmer. Born. (1929) 156, pro Elmer 21524, 21771. = Ptychophyxis bacciformis Croizat

    Koilodepas sp.: Airy Shaw, Kew Bull. 23 (1969) 84, in notes, Kew Bull. Add. Ser. 4 (1975) 140, pro SAN (Ahwing) 35474. = Lepisanthes tetraphylla (Vahl) Radlk. (Sapindaceae).