Flora of Thailand
Euphorbiaceae
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P.C. van Welzen , Q.D. Nguyen & R.C.K. Chung
Goto on this page:
Mill., Gard. Dict. ed. 4, 2. 1754; Müll.Arg. in DC., Prod. 15, 2: 1057. 1866; Pax in Engl., Pflanzenr. IV.147.ii: 21. 1910; Pflanzenr. IV.147.xvi: 194. 1924; Airy Shaw, Kew Bull. 26: 308. 1972; D.J.Rogers & Appan in Fl. Neotropica 13: 19. 1973; G.L.Webster, Ann. Missouri Bot. Gard. 81: 99. 1994; Welzen, Q.D.Nguyen & R.K.C.Chung, Rheedea 7: 79. 1997; Radcl.-Sm., Gen. Euphorbiacearum: 273. 2001; Welzen, Q.D.Nguyen & R.K.C.Chung in Welzen & Chayam., Fl. Thailand 8, 2: 437. 2007; G.L.Webster in Kubitzki, Fam. Gen. Vasc. Pl. 11: 162. 2014.— Janipha Kunth in Humb., Bonpl. & Kunth, Nov. Gen. & Sp. 2: 84 (folio), 106 (quarto), t. 109. 1817.— Mandioca Link, Handbuch 2: 436. 1831, nom. superfl.— Hotnima A.Chev., J. Agric. Trop. 8: 111. 1908.— Manihotoides D.J.Rogers & Appan, Fl. Neotropica 13: 247. 1973.
Monoecious shrubs. Roots tuberous, with large quantities of starch. Latex milky. Indumentum of simple hairs. Stipules caducous, leaving well-defined scars. Leaves alternate, simple; blade palmatifid with (1–)5(–11 or more) lobes, without glands; lobes usually obovate, usually asymmetric except for the central lobe, papery, base not to subpeltate, margin entire, glabrous, usually glaucous below; venation palmate, looped and closed near margin, usually scalariform. Inflorescences terminal or pseudo-axillary raceme-like panicles, usually several per node, branching sparingly once with short branches; lower flowers pistillate, upper ones staminate. Flowers actinomorphic, pedicelled; calyx campanulate, 5-lobed, imbricate; petals absent. Staminate flowers: stamens 10, in 2 whorls, outer whorl larger, outside disc glands, inner among disc glands, anthers subbasally dorsifixed, introrsely opening with longitudinal slits, 2-locular, connective elongated, elongation pilose; disc 10 radial glands; pistillode small. Pistillate flowers: disc annular; ovary 3-locular, one ovule per locule; style short, glabrous; stigmas 3, apically broadening, often split, at the margin with globose stigmatic glands. Fruits rhegmas, sometimes winged or ridged. Seed with a caruncle.
About 100 species in the neotropics and subtropics. Two species are introduced world-wide, M. esculenta Crantz (also in Thailand) for its edible roots and M. carthaginensis subsp. glaziovii Müll.Arg. for its latex (absent from Thailand). Classification: Subfam. Crotonoideae, tribe Micrandreae, subtribe Manihoteae.
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1a. |
Mainly small trees. Leaves distinctly (more than 5 mm) peltate. Ovary smooth. Fruits without wings. (Leaf lobes broad, lobes 0.9—3 times as long as wide; central unlobed part usually longer, lobes 5.8—12.5 times longer as basal part; nerves usually distinct and differently coloured when dry. Seeds 12 mm or longer.). |
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1b. |
Mainly shrubs. Leaves not or slightly (up to 2 mm) peltate. Ovary with 6 longitudinal ridges. Fruits with 6 longitudinal wings. (Leaf lobes narrow, c. 2.9–12.5 times as long as wide; central unlobed part usually short, lobes 15–21 times longer than basal part; nerves usually not very distinct and differently coloured when dry. Seeds up to 12 mm long). |
1. Manihot carthaginensis (Jacq.) Müll.Arg. subsp. glaziovii (Müll.Arg.) Allem, Novon 11: 160. 2001; Welzen, Q.D.Nguyen & R.K.C.Chung in Welzen & Chayam., Fl. Thailand 8, 2: 438, Fig. 39: H, I. 2007.
Not treated in this flora, cultivated once in the Bangkok area and on Krabi (Nai Chong Rubber Research Station).
V e r n a c u l a r.— Yang sia ra (ยางเซียรา) (Central), Para rubber.
U s e s.— latex provides rubber though of lesser quality than Hevea rubber.
2. Manihot esculenta Crantz, Inst. Rei Herb. 1: 167. 1766; Airy Shaw, Kew Bull. 26: 308. 1972; D.J. Rogers & Appan in Fl. Neotropica 13: 25. 1973; Veltkamp & G.H. de Bruijn in PROSEA 9: 107. 1996; Welzen, Q.D.Nguyen & R.K.C.Chung, Rheedea 7: 80. 1997; Welzen, Q.D.Nguyen & R.K.C.Chung in Welzen & Chayam., Fl. Thailand 8, 2: 438, Fig. 39: A-G. 2007.— Jatropha manihot L., Sp. Pl.: 1007. 1753.— Jatropha dulcis Gmelin, Onom. Bot. 5: 7. 1772–1778.— Janipha manihot Kurz in Humb., Bonpl. & Kunth, Nov. Gen. & Sp. 2: 84 (folio), 108 (quarto) 1817.— Manihot utilissima Pohl, Pl. Bras. Icon. Decr. 1: 32, t. 24. 1827, nom. superfl.; Müll.Arg. in DC., Prod. 15, 2: 1064. 1866; Pax in Engl., Pflanzenr. IV. 147, 2: 67, fig. 24. 1910.— Manihot dulcis (J.F. Gmel.) Pax in Engl., Pflanzenr. IV.147.ii: 71. 1910.
(Herb to) shrub (to treelet) up to 7 m high, sparingly branching; branchlets often tinged reddish. Stipules entire or somewhat split. Leaves: blade basally attached or slightly (up to 2 mm) peltate, dark green above, pale light greenish greyish underneath, sometimes variegated; lobes narrow, 2.9–12.5 times as long as wide; central unlobed part usually short, lobes 15–21 times as long as unlobed part; nerves 5–18 pairs, usually not very distinct, especially above, veins reticulate to scalariform. Inflorescences lax, with 3–5 together in fascicles. Staminate flowers: calyx divided to halfway or more, green to white to reddish, glabrous except for apex of tube and inner side of segments; filaments white, anthers yellow; disc yellow to light orange. Pistillate flowers: calyx green with red margin and midrib, hairy along the margin and on the midrib inside; disc pink; ovary with 6 longitudinal ridges, green to orange; pistil and stigmas white. Fruit subglobose, green (to light yellow, white, dark brown), with 6 longitudinal wings. Seeds up to 12 mm long.
T h a i l a n d.— NORTHERN: Chiang Mai (Doi Chiang Dao, Doi Suthep), Lamphun (Doi Khun Tan), Phitsanulok (Thung Salaeng Luang); CENTRAL: Saraburi (Sam Lan); SOUTH-EASTERN: Chanthaburi (Klung); SOUTH-WESTERN: Prachuap Khiri Khan (Pa Nam Put); PENINSULAR: Phangnga (Luk Sua Cave), Phuket (Patong Beach), Nakhon Si Thammarat (Young Falls), Pattani (To Mo). Probably in many more places.
D i s t r i b u t i o n.— Probably originally cultivated in N.E. Brazil, nowadays only known from cultivation and found throughout S.E. Asia and Malesia.
E c o l o g y.— Cultivated or found in waste places of mainly abandoned gardens and along roads, probably not escaped; locally common. Soil: clay, limestone, red loam, peaty soil, usually well-drained. Altitude: sea level up to 1700 m. Flowering and fruiting whole year through, though less so in Sep. and Oct. See also Veltkamp & de Bruijn 1996.
V e r n a c u l a r.— Tang ban (ต้างบ้าน), tang noi (ต้างน้อย) (Northern); man sampalang (มันสำปะหลัง), man samrong (มันสำโรง), sampalang (สำปะหลัง) (Central); man hio (มันหิ่ว) (Phangnga); man mai (มันไม้), man tan (มันต้น) (Peninsular); u-bi-ka-yu (อุบีกายู) (Malay-Peninsular).
U s e s.— The roots constitute one of the world’s most important stock crops for starch. It is mainly used for human consumption, less for animal consumption and (far less) for industrial purposes, though this may be very different depending on the country (Thailand mainly animal fodder). Presently, one of the most important stock crops in the North-eastern of Thailand. The roots can rarely be eaten fresh and are usually cooked, steamed, fried or roasted when fresh or after drying or fermenting. It is advisable to peel, grind or cut, and dry the roots in order to diminish the contents of cyanogenic glucosides (mainly linamarin). Only sweet cassava can be eaten fresh in small quantities (the peel contains most HCN); the bitter ones have to be treated due to a much higher HCN content. The leaves are also eaten, they contain reasonable amounts of carotene and vitamin C, though they too have to be cut in pieces and they have to be cooked to rid the HCN. Food poisoning hardly occurs, because most people know how to prepare the roots and leaves. See also Veltkamp & de Bruijn 1996. Plants, especially with variegated leaves, are also used in horticulture. No satisfactory system of classification exists for the manifold of cultivars.
N o t e.— The M. dulcis form of M. esculenta as found in the Malay Peninsula is exceptional in these characters and like M. carthaginensis.