DESCRIPTIVE CATALOGUE. 259 



branches of the filament, an imperfect pistil (pistillode) present or lacking. Female 

 flowers with a perianth like that of the male, but smaller, imperfect stamens, or 

 staminodes, 3 or 6, or lacking. Ovary 3-angled or 3-ribbed, 3-celled; styles 3, very 

 short, the stigmas entire or 2-parted, recurved; ovules 2, superposed in each cell, 

 pendulous. Fruit a berry or 3-valved capsule. 



Dioscorea aculeata. Guinea yam. Prickly yam. 



Local names.— Nika (Guam); Baliacag (Philippines) ; Kattu kelangu (Malabar); 

 Hoei'-trobong (Java); Kummara-baddu (Teloogoo). 



Stem aculeate, terete; leaves alternate, cordate, acuminate, 7to9-nerved, transverse 

 veins subsimple; male spikes panicled.a 



This brief description corresponds with some of the varieties of the ' ' nika ' ' culti- 

 vated in Guam. Seemann attributes to it the yam called by the Fijians "kawai," 

 which is in common cultivation on most of the islands of the group, and which 

 differs from the wild spiny yam called " tivoli" {D. nummularia?) in having alternate 

 instead of opposite leaves, and lacking the wiry spines about the base of the stem. 

 Hooker identifies with it Rheede's "kattu kelengu." To this species 'also was 

 assigned by Warburg the common cultivated yam of the Papuans, which he after- 

 wards found to differ from Linnseus' description in having simple male inflorescences 

 and sessile flowers; also in the broad, relatively not deep sinus of the base of the 

 leaf, and which he afterwards described as Dioscorea papuana. & Warburg further 

 remarks that the species D. aculeata is so insufficiently and badly described, that 

 perhaps a series of species is included within it. c 

 References: 



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

 Dioscorea aculeata Roxb. (not L. ). Same as Dioscorea spinosa Roxb. 

 Dioscorea alata. White yam. Square-stemmed yam. Plate xlviii. 



Local names. — Dago (Guam) ; Ubi, Ube (Philippines, Java, Malay Archipelago) ; 

 Uvi (Fiji, New Zealand); Ovi, Oviala (Madagascar); Ufi (Samoa); Uhi 

 (Tahiti); Ui-parai (Rarotonga); Heei'-prataen (Java); Hoei'-lie lien (Sunda); 

 Kap (Caroline Islands); Name (Panama). 



A cultivated yam having a 4-angled or 4- winged climbing stem without prickles. 

 Roots very large; stem stout, often tuberiferous; leaves mostly opposite, varying 

 from orbicular and deeply cordate to hastately ovate, 5 to 7-nerved ; male flowers in 

 slender fascicled spikes, very much as in D. sativa; female flowers in much stiffer 

 spikes; sepals narrowly oblong or lanceolate, subvalvate; capsule broader than long, 

 25 to 37 mm. in diameter, very broadly obcordate, coriaceous; carpels rounded; 

 seeds orbicular, broadly winged all round. 



The natives of Guam distinguish a number of varieties all of which are known as 

 "dago," with roots of different sizes and shapes, varying in color from white to pur- 

 ple and differing in time of maturity. Yams are left in the ground for a short while 

 after the vine has turned yellow and died down. The tops of the tubers are then cut 

 off with the vines attached and buried in the ground, piling the earth up around the 

 base of the vine. After several w T eeks another yam is produced which contains a 

 number of eyes or buds. This is cut up into pieces each having an eye from which the 

 new plant grows. Yams are usually planted in small hillocks arranged in a large cir- 

 cle, sometimes with a tree or high pole at the center. In each hill a slender pole is 

 thrust and inclined toward the center of the circle, the poles forming the shape of an 

 Indian tent, or all are inclined against the central tree. The ground is kept free 



« Flora Vitiensis, p. 308, 1865-73. 



&0. Warburg, Beitriige zur kenntniss der papuanischen Flora, Engler's Botanische 

 Jahrbucher, Bd. 13, pp. 273-274. 1891. 



c See Dioscorea papuana below. 



