Flora of Thailand

Euphorbiaceae

 

38. Excoecaria

 

P.C. van Welzen & H.-J. Esser

 

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Genus description

Identification key

Species descriptions

 

Excoecaria

 

L., Syst Nat. ed. 10: 1288. 1759; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.v: 157. 1912; Airy Shaw, Kew Bull. 26: 268. 1972; Whitmore; Tree Fl. Malaya 2: 96. 1973; G.L.Webster, Ann. Missouri Bot. Gard. 81: 122. 1994; Chakrab. & M.G.Gangop., J. Econ. Taxon. Bot. 18: 193. 1994; Esser, Nord. J. Bot. 16: 579. 1996; Welzen & Esser in Welzen et al., Thai For. Bull. 28: 78. 2000; Esser in Radcl.-Sm., Gen. Euphorbiacearum: 360. 2001; Welzen & Esser in Chayam. & Welzen, Fl. Thailand 8, 1: 292. 2005; G.L.Webster in Kubitzki, Fam. Gen. Vasc. Pl. 11: 204. 2014 Commia Lour., Fl. Cochinchin.: 605. 1790 Glyphostylus Gagnep., Bull. Soc. Bot. France 71: 871. 1925; Airy Shaw, Kew Bull. 26: 281. 1972.

 

Shrubs to trees, mono- or dioecious; Indumentum absent (or a very occasional stellate hair). Latex white. Stipules usually with fimbriate margin, caducous. Leaves alternate or opposite, simple, symmetric, basally attached, margin (very indistinctly) serrate to crenate, teeth glandular; venation pinnate, nerves looped and closed near margin, veins reticulate. Inflorescences racemes or a head, either with basally a few pistillate flowers and mainly staminate flowers or only flowers of one sexe. Flowers actinomorphic, bracts and often bracteoles usually (basally) with 2 glands; sepals 3; petals and disc absent. Staminate flowers: stamens 3, free; pistillode absent. Pistillate flowers: ovary 3-locular, 1 ovule per locule; styles short; stigmas short, not split. Fruits rhegmas, lobed or not, depressed-globose or globose; caruncle remaining attached to column after dehiscence. Seeds ovoid, marbled.

    According to Webster (1994) a paleotropical genus of 40 species (mainly in Southeast Asia), but according to Chakrabarty & Gangopadhyay (1994) only 35 species exist; five in Thailand, with two apparent pairs of resembling species (E. cochinchinensis and E. laotica and E. bantamensis and E. oppositifolia; E. agallocha is separate). Classification: Subfam. Euphorbioideae, tribe Hippomaneae, subtribe Hippomaninae.

 

Key to the species

 

1a.

Plants dioecious. Leaves alternate, with basally two glands in the margin at either side of the petiole. Staminate flowers in very dense catkins. --- Mangrove, littoral.

1. E. agallocha

1b.

Plants monoecious. Leaves alternate or opposite, without basal glands in the margin. Staminate flowers in open racemes or in heads.

2

2a.

Flowers in condensed heads, one or two pistillate and many staminate.

4. E. laotica

2b.

Flowers in racemes, either with basally a few pistillate flowers and apically many staminate ones, or racemes with one type of flower only.

3

3a.

Leaves alternate or opposite, (elliptic to) obovate. Inflorescences with basally a few pistillate flowers and apically many staminate ones. Staminate sepals 0.6-1 by 0.3-0.4 mm, pistillate ones 1.2-1.5 by 1-1.3 mm. Fruits less than 1 cm broad.

4

(3. E. cochinchinensis)

3b.

Leaves all opposite, elliptic. Inflorescences with one type of flower only. Staminate sepals 1.1-1.2 by 0.8-1.1 mm; pistillate ones 1.4-1.5 by 1.7-2 mm. Fruits more than 2 cm broad

5

4a.

Leaves purplish red beneath.

3a. var. cochinchinensis

4b.

Leaves green beneath.

3b. var. viridis

5a.

Fruits several on an inflorescence, 3-4 cm wide.

2. E. bantamensis

5b.

Fruits single per inflorescence, 4-6 cm wide.

5. E. oppositifolia

 

1. Excoecaria agallocha L., Sp. Pl. ed. 2: 1451. 1763; Mόll.Arg. in DC., Prodr. 15, 2: 1220. 1866; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.v: 165. 1912; Airy Shaw, Kew Bull. 26: 268. 1972; Whitmore, Tree Fl. Malaya 2: 96. 1973; Chakrab. & M.G.Gangop., J. Econ. Taxon. Bot. 18: 198. 1994; Y.C.Tseng, Fl. Reipubl. Pop. Sin. 44(3): 9, pl. 24 fig. 3-5. 1997; Welzen & Esser in Welzen et al., Thai For. Bull. 28: 79. 2000; in Chayam. & Welzen, Fl. Thailand 8, 1: 293, fig. 72a-d. 2005Commia cochinchinensis Lour., Fl. Cochinch.: 606. 1790Excoecaria camettia Willd., Sp. Pl. 4: 864. 1805Excoecaria affinis Endl., Prod. Fl. Norfolk.: 83. 1833Stillingia agallocha (L.) Baill., Ιtude Euphorb.: 518. 1858.

 

Excoagall-habit.gif (64812 bytes)    Excoagall-male.gif (45054 bytes)    Excoagall-female.gif (21927 bytes)

 

Shrubs to trees up to 15 m high, dioecious, deciduous, lenticellate. Stipules 2-2.3 by c. 0.7 mm. Leaves alternate; petiole 1.2-2.5 cm long; blade elliptic, 3.7-11 by 1.5-5.8 cm, length/width ratio 1.9-2.5, parchment-like, symmetric, base rounded with two glands in margin near insertion, margin very indistinctly crenate (with glands), apex (acute to) obtusely acuminate; nerves 12 or 13 till apex. Staminate flowers in very dense racemes up to 13 cm long, less than 1 mm diameter, yellowish green; pedicel c. 0.6 mm long; sepals triangular, 0.8-1 by c. 0.3 mm, basally often eared; stamens: filaments c. 1.7 mm long; anthers c. 0.6 by 0.4 mm. Pistillate flowers in racemes of up to 5 cm long; pedicel 1-5 mm long; sepals broadly ovate, 1.5-2 by 1.2-1.5 mm; ovary 1-1.5 mm in diameter; style 0.5-1 mm long; stigmas 2.8-3.5 mm long. Fruits lobed, depressed globose, 4.5-5 by 8-9 mm, red. Seeds not seen.

    T h a i l a n d.— SOUTH-WESTERN: Prachuap Khiri Khan (Sam Roi Yot); CENTRAL: Samut Sakhon; SOUTH-EASTERN: Chanthaburi (Khung Kra Baen, Tha Chalat), Trat (Ko Chang); PENINSULAR: Trang, Satun (Ko Tarutao), Songkhla (Songkhla Lake, Ko Yo), Narathiwat.

    D i s t r i b u t i o n.— S. India and Sri Lanka to Taiwan and the Ryu-Kyu Islands, and throughout S.E. Asia and Malesia to the Pacific.

    E c o l o g y.— Common in mangrove, tidal forest, cleared forest, brackish areas, rice fields; soil: mud, sand. Altitude: sea level (up to 50) m. Said to be poisonous.

    V e r n a c u l a r.— Tatum (), tatum thale (มท) (Central); bu-to () (Malay-Pattani).

 

2. Excoecaria bantamensis Mόll.Arg., Linnaea 32: 124. 1863; in DC., Prodr. 15, 2: 1219. 1866; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.v: 161. 1912; Airy Shaw, Kew Bull. 26: 269. 1972; Welzen & Esser in Welzen et al., Thai For. Bull. 28: 79. 2000; in Chayam. & Welzen, Fl. Thailand 8, 1: 293. 2005 Excoecaria macrophylla J.J.Sm., Meded. Dep. Landb. Ned.-Indiλ 10: 611. 1911 Excoecaria oppositifolia Griff. var. crenulata auct. non Chakrab. & M.G.Gangop.: Chakrab. & M.G.Gangop., J. Econ. Taxon. Bot. 18: 208. 1994, p.p., pro E. bantamensis, E. macrophylla.

 

Trees up to 15 m high, monoecious. Stipules 3-5.5 by c. 3 mm. Leaves opposite; petiole 1.2-1.4 cm long; blade elliptic, 7-18 by 2-5 cm, length/width ratio 3.4-3.6, coriaceous, symmetric, base cuneate, margin crenate, apex acute to shortly acuminate; nerves 14-20 till apex. Staminate inflorescences and flowers seen only very young, bracts with 2 large glandular areas. Pistillate flowers in separate racemes of up to 13 cm long, 1-1.5 mm diameter, up to more than 20 flowers per inflorescence; bracts broadly ovate, 1-1.2 by c. 0.8 mm, with large glandular areas; pedicel absent; sepals broadly ovate, c. 2 by 1.8 mm; ovary c.1.8 by 1.8 mm, style 1-1.3 mm long, longitudinally grooved, apically with abscission zones; stigmas c. 2.5 mm long, recurved. Fruits not lobed, globose, c. 4 by 4 cm high. Seeds c. 9.5 by 9.5 mm.

    T h a i l a n d.— SOUTH-WESTERN: Prachuap Khiri Khan (Huai Wa Ton); SOUTH-EASTERN: Chanthaburi (Pong Nam Ron).

    D i s t r i b u t i o n.— Thailand, Java (type), Borneo.

    E c o l o g y.— Evergreen forest. Altitude: 20-600 m.

    V e r n a c u l a r.— Tatum pa (่า) (Prachuap Khiri Khan); ko-ka-pue (าะ) (Khmer- Chanthaburi).

 

3. Excoecaria cochinchinensis Lour., Fl. Cochinch.: 612. 1790; Mόll.Arg. in DC., Prodr. 15, 2: 1215: 1866; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.v: 160. 1912; Airy Shaw, Kew Bull. 26: 269. 1972; Whitmore, Tree Fl. Malaya 2: 97. 1973; Chakrab. & M.G.Gangop., J. Econ. Taxon. Bot. 18: 199. 1994; Y.C. Tseng, Fl. Reipubl. Pop. Sin. 44(3): 7. 1997; Welzen & Esser in Welzen et al., Thai For. Bull. 28: 79. 2000; in Chayam. & Welzen, Fl. Thailand 8, 1: 295. 2005Antidesma bicolor Hassk., Cat. Hort. Bog.: 81. 1844 Excoecaria bicolor (Hassk.) Zoll. & Hassk., Retzia 1: 158. 1855 Excoecaria bicolor (Hassk.) Zoll. & Hassk. var. purpurascens Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.v: 159. 1912.

 

a. var. cochinchinensis: Welzen & Esser in Welzen et al., Thai For. Bull. 28: 80. 2000; in Chayam. & Welzen, Fl. Thailand 8, 1: 295. 2005.

 

Excococh-coch-photo1.jpg (367051 bytes)    Excococh-coch-photo2.jpg (249283 bytes)

Like other variety, only lower leaf surface deep red-purple.

    T h a i l a n d.— CENTRAL: Bangkok (Bangkhen).

    D i s t r i b u t i o n.— Originally from Indochina (type), now widely cultivated.

    V e r n a c u l a r.— Ka buea () (Ratchaburi); kamlang krabue (ลังระ), lin krabue (ระ) (Central); bai thong daeng (ดง) (Chanthaburi).

    U s e s.— Due to its two coloured leaves used as an ornamental shrub.

 

b. var. viridis (Pax & K.Hoffm.) Merr., Philipp. J. Sci. 15: 244. 1919; Welzen & Esser in Welzen et al., Thai For. Bull. 28: 80. 2000; in Chayam. & Welzen, Fl. Thailand 8, 1: 295, fig. 72e, f. 2005 Excoecaria quadrangularis Mόll.Arg. in DC., Prodr. 15, 2: 1219. 1866; Chakrab. & M.G.Gangop., J. Econ. Taxon. Bot. 18: 210. 1994 Excoecaria bicolor (Hassk.) Zoll. & Hassk. var. viridis Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.v: 159. 1912 Excoecaria orientalis Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.v: 160. 1912 Excoecaria bicolor (Hassk.) Zoll. & Hassk. var. orientalis (Pax & K.Hoffm.) Gagnep. in Lecomte, Fl. Indo-Chine 5: 406. 1926.

 

Excococh-fruit.gif (38755 bytes)

 

Shrubs up to 2 m high, monoecious, glabrous. Stipules 2-2.2 by 0.8-1 mm. Leaves alternate to opposite; petiole 4-11 mm long; blade (elliptic to) obovate, 4.2-14 by 0.9-4.4 cm, length/width ratio 3.2-4.7, papery to rather coriaceous, symmetric, base cuneate, margin serrate/crenate with glandular teeth, apex acuminate to cuspidate, acumen 6-18 mm long; nerves 9-10 till apex. Inflorescences racemes with basally a few pistillate flowers and in the upper part many staminate flowers, up to 5 cm long; bracts and bracteoles with glands; flowers green to yellow. Staminate flowers 1-1.5 mm diameter; pedicel 0.6-0.8 mm high; sepals triangular, 0.6-1 by 0.3-0.4 mm, margin fimbriate; stamens: filaments 0.8-1.1 mm long; anthers 0.5-0.7 by 0.4-0.5 mm, creamish. Pistillate flowers 2-2.8 mm in diameter; pedicel 0.4-1(-3 in fruit) mm long; sepals ovate, 1.2-1.5 by 1-1.3 mm; ovary 1-1.5 by 1-1.8 mm diameter; styles 0.3-0.6 mm long; stigmas 1.9-2.5 mm long. Fruits lobed, depressed globose, c. 7 by 5 mm high, red. Seeds not seen.

    T h a i l a n d.— NORTHERN: Chiang Mai (Doi Angka, Doi Inthanon); NORTH-EASTERN: Loei (Phu Kradueng), Nakhon Phanom (Phu Langka), Khon Kaen (Donglen); EASTERN: Chaiyaphum (Nam Phrom), Nakhon Ratchasima (Khao Yai, Salika Forest); SOUTH-WESTERN: Kanchanaburi (Erawan), Phetchaburi (Kaeng Krachan), Prachuap Khiri Khan (Bang Saphan, Huai Hin Chuang); CENTRAL: Nakhon Nayok (Khao Yai National Park); SOUTH-EASTERN: Chanthaburi; PENINSULAR: Phangnga (Than Luk Sua), Krabi (Khao Pra-Bang Khram), Nakhon Si Thammarat (Yong Waterfalls), Pattani (Sai Khao Waterfalls).

    D i s t r i b u t i o n..— Myanmar, Thailand, Malay Peninsula, S. China, Indochina (type) and perhaps Taiwan.

    E c o l o g y.— Evergreen forest, mixed or deciduous forest or scrub, secondary forest, often by streams; scattered to locally common; soil: sandstone. Altitude: sea level to 1520 m.

    V e r n a c u l a r.— Tatum kai (), tatum nok () (Prachuap Khiri Khan); krabue chet tua (), lin krabue khao (ระ) (Central, Chanthaburi).

    U s e s.— Latex is said to be poisonous, it irritates the skin and mucous membranes.

 

4. Excoecaria laotica (Gagnep.) Esser, Nord. J. Bot. 16: 580. 1996; Welzen & Esser in Welzen et al., Thai For. Bull. 28: 80. 2000; Welzen & Esser in Chayam. & Welzen, Fl. Thailand 8, 1: 296, fig. 72g, fig. 73. 2005 Glyphostylus laoticus Gagnep., Bull. Soc. Bot. Fr. 71: 871. 1925; Airy Shaw, Kew Bull. 26: 281. 1972.

 

Excolaot-habit.gif (25847 bytes)   

 

Shrubs to treelets up to 2 m high, monoecious, glabrous. Stipules 0.3-1.5 by 0.5-0.6 mm. Leaves opposite; petiole c. 5 cm long; blade (elliptic to) obovate, 4.2-13.5 by 1.9-4.5 cm, length/width ratio 2.2-3, coriaceous, symmetric except often for the base, base obtuse, margin serrate with glands, apex acuminate; nerves 9-12 till apex. Flowers in dense heads with basally a pistillate flower and many staminate flowers, up to 2 cm long; bracts with glands, bracteoles more or less without. Staminate flowers c. 2 mm in diameter, light green, sessile; sepals triangular, 1.25-2.5 by 0.5-1.5 mm; stamens: filaments 1.6-5 mm long, white; anthers 0.6-0.7 by c. 0.4 mm, whitish. Pistillate flowers c. 2 mm in diameter, subsessile, green to reddish; sepals ovate, c. 1.6 by 1.8 mm; ovary c. 2 by 2 mm; styles 0.8-3 mm long; stigmas 0.9-1.25 mm long. Fruits lobed, depressed globose, 8-12 by 5-6 mm high, red. Seeds 4.5-5 by 4.5-5 mm.

    T h a i l a n d.— EASTERN: Nakhon Ratchasima (Khao Phrik); NORTH-EASTERN: Loei (Phu Kradueng), Khon Kaen (Dong Lan); SOUTH-WESTERN: Kanchanaburi (Erawan National Park); PENINSULAR: Pattani (Sai Khao Falls).

    D i s t r i b u t i o n.— Laos (type), Thailand

    E c o l o g y.— (Dry) evergreen forest, moist deciduous forest, disturbed primary evergreen forest, along streams; locally common; soil: limestone. Altitude: 50-600 m.

    V e r n a c u l a r.— Tatum lao (ลา) (General).

 

5. Excoecaria oppositifolia Griff., Calcutta J. Nat. Hist. 4: 386. 1844; Mόll.Arg. in DC., Prodr. 15, 2: 1219. 1866; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.v: 161. 1912; Airy Shaw, Kew Bull. 26: 270. 1972; Whitmore, Tree Fl. Malaya 2: 96. 1973; Chakrab. & M.G.Gangop., J. Econ. Taxon. Bot. 18: 207. 1994; Welzen & Esser in Welzen et al., Thai For. Bull. 28: 80. 2000; Welzen & Esser in Chayam. & Welzen, Fl. Thailand 8, 1: 298, fig. 72h. 2005.

 

    Excooppo-habit.gif (30293 bytes)

 

(Shrubs to) trees up to 13 m high, monoecious. Stipules c. 5 by 4 mm. Leaves opposite; petiole 1.3-2.5 cm long; blade elliptic, 9.5-29 by 3.7-12 cm, length/width ratio 2-3.4, coriaceous, symmetric, base rounded, margin (indistinctly) serrate, apex acute to acuminate; nerves 14-20 till apex. Flowers in separate racemes. Staminate flowers in loose racemes up to 26 cm long, c. 1.5 mm in diameter, greenish; bracts (without to) with 2 large glandular areas; pedicel 0-0.5 mm long; sepals ovate, 1.1-1.2 by 0.8-1.1 mm; stamens: filaments 1-1.5 mm long; anthers c. 0.5-0.8 by 0.9-1 mm. Pistillate flowers not seen, single, terminal on short rachis, latter 1.2-1.7 cm long in fruit, c. 1.5 mm diameter; bracts ovate, 1.3-1.5 by 1-1.2 mm, with large glandular areas; pedicel 2-4 mm long; sepals broadly ovate to triangular, 1.5-3 by 1-1.7 mm; ovary unknown; style up to 2 mm long in fruit, stigmas c. 2.3 mm long, recurved. Fruits not lobed, globose, 4-6 by 4-5.5 cm high, green; column c. 8 mm long. Seeds 10-11 by 10-11 mm high.

    T h a i l a n d.— NORTHERN: Nan (Doi Pha Chang), Lampang (Mae Peng, Wang Fen); NORTH-EASTERN: Loei (Pa Pakchom); EASTERN: Nakhom Ratchasima (Khao Yai National Park); SOUTH-WESTERN: Kanchanaburi (Thung Yai Naresuan), Phetchaburi (Kaeng Krachan National Park); CENTRAL: Nakhon Nayok (Khao Yai National Park); SOUTH-EASTERN: Chon Buri (Khao Kampang), Chanthaburi (Khao Soi Dao, Pong Nam Ron); PENINSULAR: Surat Thani (Ko Samui).

    D i s t r b u t i o n.— Assam (type), Myanmar, Thailand, Indochina.

    E c o l o g y.— Evergreen forest, mixed deciduous forest, usually along streams: soil: varying from acid rock to shale to limestone. Altitude: 80-800 m.

    V e r n a c u l a r.— Tang ta bot (ัง), yang ron (าง) (Northern); fai duean ha (ไฟดื้า) (Peninsular).