DOKSTENIA 
35 6 
whose edge project a number of bracts. The perianth-segments are 
completely united to one another. Sta. in the fir. usually 2. The 
fruit when ripe is shot out of the receptacle; the latter becomes very 
turgid and presses on the fruit and at length ejects it as one might fillip 
away a bit of soap between finger and thumb. 
Doryalis = Dovyalis E. Mey. 
Doryanthes Correa. Amaryllidaceae (11). 3 sp. Austr. 
Dorycnium Linn. Leguminosae (ill. 5). 10 sp. Medit. 
Douglasia Lindl. Primulaceae (1). 3 sp. arctic N. Am., r Spain to 
Italy (alpine, see p. 147)- 
Dovyalis E. Mey. Flacourtiaceae. 3 sp. S. Afr., Madag. See Aberia. 
Placed in Bixineae by Benth. -Hooker. 
Downingla Torr. (inch Clintonia Dough). Campanulaceae (ill.)* 3 S P* 
Oregon, Calif., Chili. D. pulchella Torr. has no twisting of the 
floral axis, or not more than 90°. 
Draba Dill, ex Linn. Cruciferae (iv. 14). 150 sp. N. temp, and 
arctic, and south-west. N. Am., 5 in Brit, (whitlow-grass). Most are 
tufted xerophytes with hairy or fleshy leaves. 
Dracaena Vand. Liliaceae (vi). 40 sp. Old World trop. Mostly 
trees, whose stems branch and grow in thickness (by a peculiar ‘ extra- 
fascicular ’ cambium, see text-books of anatomy). The famous dragon- 
tree of Teneriffe ( D . Draco L.), which was blown down in 1868, was 
70 ft. high and 45 ft. in girth and was supposed to be 6000 years old. 
A resin exudes from the trunk of this sp., known as dragon’s blood. 
Dracocephalum Linn. Labiatae (vi. 3). About 40 sp. Eur., Medit., 
As., and 1 in N. Am. 
Dracontium Linn. Araceae (iv). 6 sp. trop. Am. The sympodial 
rhizome gives rise yearly to one enormous leaf and an infh The leaf 
has 3 chief divisions, and the lateral ones develope dichotomously at 
first. Fir. g with perianth. 
Dracophyllum Labill. (inch Sphenotoma R. Br.). Epacridaceae. 26 sp. 
N. Z. , Austr. , New Caled. The sheathing leaves leave ring-scars when 
they fall. 
Dracunculus (Tourn.) Adans. Araceae (vii). 2 sp. Medit. Fertilised 
like Arum. 
Drimia Jacq. Liliaceae (v). 15 sp. Afr. 
Drimiopsis Lindl. et Paxt. Liliaceae (v). 5 sp. S. and trop. Afr. 
Drimys Forst. Magnoliaceae (3). 10 sp. S. Am., and N. Z. to Borneo. 
There is a distinction between calyx and corolla (cf. Illicium). The 
bark of D. Winteri Forst. (Winter’s bark) is medicinal. 
Drosera Linn. Droseraceae. 90 sp. trop. and temp. 3 in Brit, of 
which D. rotundifolia L., the sundew, is abundant in bogs. They are 
herbs usually with creeping rhizomes and rosettes of leaves. The blade 
of the leaf is circular in some sp., elongated in others, and is set with 
curious tentacles; these are emergences (p. 114) containing vascular 
bundles and ending in swollen reddish heads which secrete a sticky 
