Volume 8 > Part 1 > Year 2005 > Page 290 > Euphorbiaceae > Euphorbia

25. Euphorbia milii Des Moul.wfo-0000963364

Bull. Hist. Nat. Soc. Linn. Bordeaux 1: 27, pl. 1. 1826; Croizat, J. Arnold Arbor. 21: 506. 1940; Radcl.-Sm., Kew Bull. 26: 266. 1972; P.H.Hô, Câyco Viêtnam 2, 1: 359, pl. 4665. 1992; J.S.Ma, Fl. Reipubl. Popularis Sin. 44(3): 58, pl. 14, fig. 1–4. 1997.

Accepted Name : This is currently accepted.

Synonyms & Citations :

Description : Erect shrub, succulent, spiny, terete, bark brown to greyish; younger branches ca 8 mm in diam. Spines in spirals or in indistinct rows not on spineshields, solitary or in groups of 3 or more 16–25 mm long, grey to brown. Glabrous. Leaves subsessile; blade obovate elliptic, ca 1.5–5 by 0.8–2 cm, base attenuate, margin entire, apex obtuse-mucronate; venation hardly visible. Cyathia several in exserted dichasia with long peduncles; bracts at branching 2 mm long, membranous, inconspicuous; bracts below cyathia in pairs, red or yellow or white or in various colours, showy and petaloid, 1–2 cm long; cyathia sessile in bracts, glands 4, without appendages. Fruits and seeds not seen, the seeds described or 3–4 mm long, brownish.

Distribution : Origin Madagascar, widely cultivated elsewhere.

Vernacular : Wan mung mueang (ว่านมุงเมือง)(Mae Hong Son); phra chao rop lok (พระเจ้ารอบโลก), poi sian (โป๊ยเซียน), rawing rawai (ระวิงระไว), wan khem phaya in (ว่านเข็มพญาอินทร์)(Chiang Mai); mai rap khaek (ไม้รับแขก)(Central).

CommonName : Christ Thorn, Crown of Thorn.

Uses: Widespread ornamental shrub in gardens and houses, in the temperate zones as indoor plant. In Thailand widely grown and bred in numerous forms and varieties. It flowers nearly continuously.

Notes: The typical Crowns of Thorns bred in Thailand are a hybrid between Euphorbia milii and a related species from Madagascar and are correctly called Euphorbia × lomi Rauh, Kaleteen Sukk. 30: 257. 1979 (E. milii Des Moul. × E. lophogona Lam.). They are distinguished From true E. milii by the spines in groups of irregular number and larger cyathial bracts. The horticultural taxonomy was discussed by Jankalski Cact. Succ. J. (USA) 72: 202–204. 2002.