1. DioscoREA.] 152.DIOSCOREACE.E. 



7. D. alata, L. Merom-tuar sanga, K. ; Sans, S. ; Kham-alu. Beng., 



Or. 

 A very stout twiner with large tubers proceeding direct from the 

 base of the stem which has sometimes scattered prickles below and 

 on the petiole-bases, is compressed or strongly 4-angled at the base 

 and 4-inany-winged above. Leaves mostly opposite, glabrous, lower 

 very broadly ovate cordate wdth a very broad sinus, often 8 by 6" 

 and suddenly cuspidate, 9-costate with lowest costa forked, trans- 

 verse sec. n, sub-scalariform ; upper leaves smaller and narrower, 

 those on the flowering branches often lanceolate 3" by 1-2" or less, 

 acuminate, 5-costate of Avhich 3 reach apex, always somewhat cordate 

 at base. Male spikes with zigzag winged rhachis • 4-- 7" long, 2-3-nate 

 or sub-verticillate on axillarj^ branches, one flower at each angle of 

 the spike as in Haniiltonii. Fls. subglobose, -05", sep. ell. -oblong 

 rounded and concave • 05" long, pet. little shorter obovate, st. 6 perfect 

 short, in central column around small pistillode. Fem. spikes 4-8" 

 long axillary solitary sometimes forming large brachiate panicles by 

 suppression of upper leaves, young fruit shortly stoutly beaked and 

 wings with thickened margins, sep. attain • 12" long, thick concave 

 boat-shaped but sharply convex rather than keeled outside, concave 

 within, petals broadly obovate or subquadrate, vevy thick and flesh3\ 



This is the commonly cultivated yam of Chota Nagpur, and apparently occurs 

 all over the province, but flowers have only been collected in Chota Nagpur, and I 

 have not seen the ripe capsules. Fl. (and unripe capsules) Oct.-Dec. Not known 

 wild. 



It appears very close to Hamiltonii and chiefly distinguishable by the much 

 stouter, often armed strongly angled or winged stems, larger broader coarser 

 leaves and winged rhachis of male spikes. In my specimens the female has broad 

 lamellate staminodes at base of petals, much more conspicuous than those of 

 Hamiltonii, but I have examined too few specimens to make this a key character. 



Prain (in Bengal Plants) gives several varieties, but these are from the shape 

 and coloui' of the tubers only. Our plant has usually large irregidarly clavate 

 tubers with a narrow neck at the stem, white within and pinkish outside, and comes 

 apparently under the variety rubella (syn. B. rubella, Roxb.) to which the Bengali 

 name Guraniya-ulu is given. 



D. alata bears large geminate bulbils not seen in Hamiltonii, often many on 

 special branches, mostly oblong brown with a tessellated or longitudinally cracked 

 corky surface ; they attain 3" by 1-2". 



8. D. bulbifera, L. Syn. D. sativa, L. ; Pisika, Ho. ; Harad-bo, M. ; 



Bengo-nari, *S'. ; Pita-alu, Or. 

 Stems smooth, sometimes sub-alate, from a large brown sub- 

 globose rhizome covered with roots and prominent eyes not bearing 

 other tubers. Leaves altei'nate, rarely opp., suborbicular or broadly 

 ovate, abruptly caudate and usually deeply cordate. Male flowers 

 green or purple in numerous long very slender axillary and panicled 

 spikes 1-3-5" long, sepals and petals linear. Fem. spikes slender, 

 drooping, several fascicled at each axil, sepals and petals as in male. 

 Capsule broadly oblong -75" by •4-- 5", reflexed. 



Common. Purneah ! Santal Parg. ! Throughout Chota Nagpur ! Bonai, 

 Cooper ! Angul ! No doubt throughout the province. Fl. Aug. -Sept. Fr. Nov. 



A very distinct species. Bulbils common, axillary, roundish, brown with 

 prominent numerous uniformly distributed tubercle-like eyes exactly like the 

 rhizome on a small scale. Stem sometimes with 10-15 small crisped wings (var. 

 crispata, Prain, syn. D. crispata, Roxb.). L. often 10" long and broad, sometimes 



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