THE BONA VIST, LABLAB, OR HYACINTH BEAN. 3 
the flowers, and the size of the panicles. In many sorts the panicles are short 
peduncled and 10 to 20 flowered, while in the more floriferous kinds the long- 
stalked panicles are a foot in length and 20 to 30 flowered. 
Pods. — The pods vary greatly in size and shape (PI. I). The color may be 
green, white, purple, or purple margined. In some of the green-podded sorts 
the pods are fibrous and retain their shape when fully ripe, but most of the 
cultivated varieties have more or less fleshy pods, which shrink and become 
distorted at maturity. The fleshy-podded sorts are the best for use as snap 
beans. 
Seeds. — The seeds vary greatly in size, shape, and color (PI. II), and fur- 
nish along with the pods the easiest characters by which to identify varieties. 
Susceptibility to disease. — All of the varieties of the bonavist are remarkably 
free from leaf diseases. Many, if not all, however, are subject to both Fusarium 
root-rot and to nematodes. 
VALUE FOR HUMAN FOOD. 
The green pods of some varieties of the bonavist are much used 
in the Tropics as snap beans ; indeed, they have been called by Rox- 
burgh " the kidney beans of the Asiatics." Other varieties are not 
thus eaten in India, being called bitter. One variety has for some 
years been sold by Vilmorin under the name " Stringless " ( S. P. I. 
No. 20447). This produces an abundance of large, fleshy white pods, 
which, cooked after the manner of string beans, are very good. This 
variety should be generally grown from Maryland and Kentucky 
southward, as it not only produces an abundance of edible pods, but 
incidentally makes an attractive arbor vine. 
The use of the dry seeds for food is less common, but some varieties 
are thus utilized in India and China. 
Under some conditions prussic acid is formed in the seeds. Thus 
Leather (8) 1 found that the poisonous acid was formed when the 
crushed seeds of the bonavist were allowed to remain in cold water a 
few hours. 
Mr. O. F. Black, chemical biologist of the Office of Drug-Plant, 
Poisonous-Plant, Physiological, and Fermentation Investigations, 
who upon request examined seeds of S. P. I. Nos. 8356 (blackish), 
22025 (dark purple), and 25156 (cream color), all grown at Arling- 
ton Farm in 1913, to see if hydrocyanic acid could be detected, made 
the following report: 
The dry seeds were ground, suspended in dilute sulphuric acid, and distilled 
with steam. The distillate was tested for hydrocyanic acid, with negative 
results in every case. 
Nos. 8356 and 22025 were germinated in the greenhouse in sphagnum moss 
until the roots were 3 to 4 centimeters long and then tested in a similar way, 
but gave no evidence of the presence of hydrocyanic acid. 
1 The numbers in parentheses refer to " Literature cited," page 15. 
