262 USEFUL PLANTS OF GUAM. 



take note of it. In connection with this it is remarked that the D. aculeaia L. is 

 described so insufficiently and badly that perhaps a series of .species is included 

 within it.« 



References: 

 Dioscorea papuana Warb. Engler's Bot. Jahrb. 13: 273. 1891. 

 Dioscorea sativa. Round-stemmed yam. Negro yam. Common yam. 



Local names. — Dago (Guam); Bayog cabayo, Baong, Baliiicag (Philippines); 

 Hoi (Tahiti, Hawaii); Oi (Rarotonga); Pua-hoi (Marquesas); Hoei-oepas 

 (Sunda); Kaile (Fiji). 



Closely allied to D. alata, but with round instead of 4-winged stems. Quite gla- 

 brous; stem sometimes prickly below, bulbiferous, slender, green or purple; tubers 

 large, variable in form, white or yellowish within, soon decaying when taken from 

 the ground; leaves opposite or alternate, very variable in size, sometimes attaining 

 35 cm. in length and breadth, membranous, dark green, usually very deeply cordate, 

 but sometimes with only a shallow, broad sinus, acuminate, cuspidate, or caudate, 

 7 to 9-costate; male spikes slender, panicled, almost capillary, 2.5 to 10 cm.' long; 

 flowers crowded or scattered, very variable in size, green or purplish; sepals narrow, 

 linear or linear-lanceolate, 2.5 to 6 mm. long, fleshy; petals rather narrower; fila- 

 ments much shorter than the perianth; anthers minute, didymous; pistillode3-lobed; 

 female spikes axillary, solitary, or fascicled, 10 to 25 cm. long, pendulous; flowers 3 

 to 6 mm. long; sepals as in the male; capsule quadrately oblong, 16 to 25 mm. by 8 to 

 13 mm. long, membranous; seeds with a broad basal wing. This species is regarded 

 by Hooker and by Bentham as the true I), sativa of Linnaeus. The capsule is rather 

 broader upward, the top truncate or abruptly acute, the base truncate or subcordate. 

 References: 

 Dioscorea sativa L. Sp. PI. 2: 1033. 1753. 

 Dioscorea spinosa. Spiny yam. Wild yam. Plate xlix. 



Local names. — Gado, Nika cimarron (Guam); Turigo Torigo (Philippines); 

 Mou-aloo (Calcutta). 



Tubers very large; base of stem beset with long woody, rigid fibers, bearing lateral 

 spines 12 mm. long; & glabrous or tomentose; stem round, very spinous at the base; 

 leaves orbicular-cordate or reniform-cordate, 20 cm. long and broad; acuminate or 

 cuspidate, 5 to 7-nerved, rather membranous, basal lobes rounded; male flowers in 

 simple or nearly simple axillary spikes, 15 to 45 cm. long, distant or in distant 

 clusters; flowers 3 mm. in diameter, often in very dense cymules, sessile or shortly 

 pediceled; bracteoles very broad; perianth lobes remote from the large oblong 

 pistillode; sepals broadly oblong or orbicular; stamens 6, all having anthers; anthers 

 large; female raceme rather short; capsule broader than long, 2.5 cm. in diameter, 

 broadly obcordate. 



To this species should be referred D. aculeata of Roxburgh (not L. ). Linnaeus' s 

 species of that name is Rheede's "kattu kelangu," which has panicled male spikes. 

 In Fiji a thorny yam, called "tivoli" by the natives, grows in the woods, which 

 Seemann considers to be D. nummularia Lam. ( ' This plant differs from D. aculeata, 

 according to Seemann, in having opposite instead of alternate leaves. The base of 

 its stem is spiny; leaves ovate or oval, scarious-mucronate, with the base subcordate 

 or rather rotundate, 5-nerved, glaucescent below; spikes axillary; wings of the cap- 

 sule hemispherical. Hooker does not recognize D. nummularia among the Indian 

 yams. 



The gado, or spiny yam, is very abundant in Guam. Its vernacular name is iden- 

 tical with the Malayan ' ' gadong ' ' , applied to D. hirsuta. It is the only species growing 



« Warburg, Beitriige zur Kenntniss der papuanischen Flora, Engler's Botanische 

 Jahrbiicher, Bd. 13, pp. 273, 274, 1891. 

 & See p. 68. 

 cEncyc, vol 3, p. 231, 1789. 



