70 FLORA OF JAMAICA Pachyrrhizus 



America and Asia, indigenous, or cultivated on account of its 

 edible, tubei'ous root. 



P. tubePOSUS Spreng. Syst. iv. Cur. Post. 281 (1827); Kew 

 Bull. 1889, 17; OUv. in Hook. Ic. PI. t. 1843; Jam. Bull. 

 1893, 44. Phaseolus radice tuberosa &c. Plum. Cat. 8 & PI. 

 Amer. (Burm.) t. 220. Dolichos tuberosus Lam. Encyc. ii. 296 

 (1786); Macf. Jam. i 285; Descourt. Ft. Ant. viii. 127, t. 554. 



Yam Bean. 



Cultivated, and possibly uative, in Jamaica, some other W. Indian 

 Islands, and tropical S. America ; probably native in S. America. 



Stem 10-20 ft. with a large tuberous root. Leaflets, 10-17 cm. 1. and 

 br., terminal rhomboid, shortly acuminate, lateral very unsymmetrical, 

 somewhat triangular, mostly entire. Inflorescence, clusters of 2 or 3 

 flowers, more or less crowded along the upper part of the long stalk. 

 Calyx about 1 cm. 1. Corolla white, 1'5 to nearly 2 cm. 1. ; 2 calli at 

 base ; auricles turned up on the standard and the inner edge folded out- 

 wards ; claw short ; wings as long as the standard, the auricle with an 

 awl-shaped or tail-like projection ; keel a little longer than the wings, 

 auricle very small, tooth-like, a pocket-like fold on the outside near the 

 auricle. Pod 2 dm. 1., about 2 cm. br., 6-8-seeded, with reddish hairs; 

 beak 3 cm. 1., sharply triangular. Seeds 1*3 cm. 1., 1 cm. br., generally red. 



The tuberous roots afford a plentiful supply of wholesome food ; the 

 produce of three plants is usually a bushel ; the young pods are used like 

 French Beans. For further information see Macfadyen and Jamaica 

 Bulletin {loc. cit.). 



P. crosus Urb. (P. angulatus L. C. Rich.) is also cultivated in some of 

 the W. Indian Islands (though not in Jamaica) as well as in the tropics 

 of the Old World. It differs in the leaflets with angular lobes, the flowers 

 violet-coloured, and the pods about half the length of those of P. tuberosus.'} 



[DOLICHOS L. 



Shrubby twining herbs with the habit of Phaseolus. Leaves 

 pinnately 3-foliolate. Flowers clustered at node-like thickenings 

 along the rhachis of a raceme ; peduncle long, bearing a leaf. 

 Calyx campanulate, shortly 4-lobed. Standard transversely 

 elliptical, with a large 4-lobed callus extending from the middle 

 to the base, forming a small auricle on each side ; keel curved 

 at a right angle. Uppermost stamen free, the rest united ; 

 anthers uniform. Style flattened upwards, narrowed at the base, 

 hairy along the upper edge below the terminal stigma. Pod 

 compressed, oblong, slightly recurved, beaked, 2-4-seeded, with 

 some tissue between the seeds. 



Species about 30, natives of the tropics. 



D. lablab L. Sp. PI. 725 (1753); Benth. in Fl. Bras. xv. 

 pt. 1, 197, t. 51,/. II.; Griseh. Fl. Br. W. Ind. 196. Phaseolus 

 maximus perennis floribus &c. Sloane Cat. 67, 68 & Hist. i. 177, 

 t. 113. Lablab vulgaris Savi Diss. 19, t. 19,/. 8 (1821) ; Macf. 

 Jam. i. 290; Urh. Symh. Ant. iv. 312. Type in Herb. Linn. 



