DIOSCOREACEAE 151 
26. DIOSCOREACEAE (YAM or Usr FAMILY) 
“Usually twining vines, snooth or armed, from fleshy rootstocks. Leaves 
simple or digitately 3- to 7-foliolate. Flowers small, in spikes, racemes, or 
panicles, unisexual. Male flowers: Perianth 6-lobed. Stamens inserted 
at the base of the perianth or on its lobes, 3 or 6, or sometimes 3 perfect 
and 3 staminodes. Rudimentary ovary present or wanting. Female 
flowers similar to the males. Staminodes 0, 8, or 6. Ovary 3-winged, 3- 
celled; ovules 2 in each cell. Capsules 3-valved, 3-winged. Seeds winged. 
Genera 9, species about 225, of wide tropical distribution, 2 genera and 
18 or more species in the Philippines. 
1. DIOSCOREA Linnaeus 
Characters of the Family as given above. (In honor of Dioscorides, a 
famous Greek physican and botanist.) 
Species 150 or more, warmer parts of both hemispheres, about 15 in the 
Philippines. 
1. Leaves simple. 
2. Stems 4-angled or 4-winged......................:cssssscsseessesceseceneeseeseeens 1. D. alata 
2. Stems terete, not at all angled or winged. 
3. Unarmed, glabrous; leaves 7- or 9-nerved, ovate, slenderly acuminate. 
2. D. bulbifera 
3. Somewhat spiny, pubescent; leaves orbicular to reniform, 11- to 15- 
Eg MERE es RE TE RB ANAS oP eae Sa EE 3. D. fasciculata 
1. Leaves 3-foliolate; stems spiny...................0.220.c..0cc-se0ceeeeeseeeee 4. D. daemona 
PCH DasOr. fsTOlmlebe. see Ee 5. D. pentaphylla 
*1. D. auaTta L. Ubi (Tag., Il, Vis.). 
A twining glabrous vine from large tuberous roots, the stems acutely 
4-angled or narrowly winged, often bearing axillary bulbils. Leaves op- 
posite, oblong-ovate, 8 to 16 cm long, 3 to 8 em wide, sharply acuminate, 
base cordate, 7- to 9-nerved, the basal lobes rounded. Staminate inflores- 
cence axillary, narrowly paniculate, up to 30 cm in length, the flowers 
alternate, on the short, zigzag, fasciculately and racemosely arranged 
spikes, greenish, 1 to 1.5 mm long. 
Commonly cultivated for its edible tubers, fl. Oct—Nov.; widely dis- 
tributed in the Philippines, but certainly not indigenous. India to Malaya. 
2. D. bulbifera L. 
A glabrous, unarmed, herbaceous vine reaching a length of several 
meters, the stems terete. Leaves simple, 7 to 14 cm long, ovate, acuminate, 
base broad, prominently cordate, the sinus broad and rounded, the lobes 
rounded, 7- or 9-nerved. Spikes slender, panicled, numerous, 8 to 10 cm 
long, rather densely many-flowered, the flowers about 3 mm long. Axils 
often bulbiferous. 
In thickets, occasional, fl. Aug.; of local occurrence in the Philippines. 
India to Malaya. 
3. D. fasciculata Roxb. Tungo (Tag.); Tugue (Il.); Tamis (Vis.). 
A slender somewhat pubescent vine reaching a height of several meters, 
the stems with scattered sharp spines. Leaves simple, suborbicular to 
reniform 6 to 12 cm long, apiculate, base 11- to 15-nerved, prominently 
cordate, lobes rounded. Spikes slender, axillary, pubescent, up to 50 cm 
long. Flowers green, about 4 mm in diameter. 
In dry thickets, occasional, fl. June-Aug.; widely distributed in the 
Philippines. India. 
