DORS TENIA 
355 
the pitcher itself, but must be taken up by the roots. It is also sup- 
posed that the pitchers are useful in condensing for re-absorption the 
vapour transpired by the numerous stomata upon their inner walls. 
Developmental study shows the pitcher to be a leaf with its lower 
side invaginated. The existing sp. of D. illustrate all stages in the 
process. Many, e.g. D. bengalensis Colebr., have bi-convex leaves; 
others have the under surface concave, e.g. D. (C.) Colly ris Wall., 
and the roots are developed under and sheltered by the concave 
leaves. From this stage a further invagination would lead to D. 
Rafflesiana. For further details of this interesting genus, see Treub 
in Ann. Buitenz . in. 1883, Haberlandt’s Tropenreise , p. 168, and two 
papers in Ann. of Bot. 1893. 
DiscMsma Choisy. Scrophulariaceae (11. 9). 9 sp. S. Afr. 
Disciflorae (Benth. -Hooker). The 2nd series of Polypetalae (p. 133). 
Disporum Salisb. Liliaceae (vn). 12 sp. N. temp. As. and Am. 
Dissochaeta Blume. Melastomaceae (1). 25 sp. Indo-mal., Philippines. 
Distegunthus Lem. Bromeliaceae (1). 1 sp. Cayenne. 
Distichlis Rafin. Gramineae (x). 4 sp. in salt places, Am. D . mari- 
tima Rafin. is also found in Austr. and is used for binding sandy soil 
(cf. Ammophila, Carex). 
Ditassa R. Br. Asclepiadaceae (11). 60 sp. S. Am. 
Dodartia (Tourn.) Linn. Scrophulariaceae (11. 8). 1 sp. S. Russia, 
W. As. 
Dodecatheon Linn. Primulaceae (iv). 5 sp. N. Am., N.E. As. Like 
Cyclamen. 
Dodonaea Linn. Sapindaceae (11). 46 sp. Austr., Sandw. Is., Madag. 
Dolichandrone Fenzl. Bignoniaceae (11). 7 sp. Madag. to Malaya. 
Dolichos Linn. Leguminosae (ill. 10). 30 sp. trop. D. Lablab L. is 
largely cultivated in the tropics for its edible pods, which are cooked 
like kidney beans. D. bijlorus L. the Horse-gram, is cultivated in 
India, &c. for feeding horses and cattle. 
Bombeya Cav. Sterculiaceae. 40 sp. Afr. 
Dondia Spreng. = Hacquetia Neck. 
Donia G. et D. Don = Clianthus Soland. 
Doodia R. Br. Polypodiaceae. 5 sp. Ceylon to Austr. 
Dorema D. Don. Umbelliferae (7). 4 sp. W. Centr. As. D. a?nmo- 
niacum D. Don is the source of the gum-ammoniacum used in medicine ; 
it is obtained by puncturing the stem. 
Doronicum Toum. ex Linn. Compositae (vm). 25 sp. N. temp. Two 
sp. are naturalised in parts of Britain. 
Dorstenia Plum, ex Linn. Moraceae (1). 50 sp. trop. Am., Afr., 1 As., 
often grown in hot-houses. Herbs or shrubs with peculiar cymose infl. 
The common receptacle of the firs, is a flat or hollowed fleshy structure, 
often more than an inch wide. The flrs. are unisexual, sometimes all 
of one sex on one receptacle, sometimes intermingled with several 
males round one female. They are sunk in the receptacle, round 
23—2 
