American Algce, to which we have been i 

 largely indebted, [M. J. B.] | 



DASYLIRION. A genus of Bromeliacem, | 

 consisting of Mexican plants with short 

 stems, and densely crowded linear leaves I 

 which droop gracefully, and generally have 

 a little brush-like tuft of fibres at the ! 

 point. From amid these leaves the flower- j 

 stalks rise to a considerable height, the j 

 upper portion being crowded with a dense | 

 I panicle of flowers, which are dioecious. 

 j The perianth consists of six nearly equal 

 ! segments in two rows ; and there are six j 

 [ stamens with filaments thickened in the , 

 ! middle, and having a gland at the base. 



■ The female flowers differ in having anther- 

 '■ less stamens, a superior six-seeded one- 

 i celled ovary, with membranous angles, 



the six ovules in pairs ; a short style with 

 a dilated three-lobed stigma ; and a nut- 

 like fruit, oue-seeded by abortion. B. 

 acrotrichum is a handsome kind grown in 



. greenhouses. [M. T. M.] 



DASYLOMA. The generic name of plants 



; belonging to the umbelliferous order, 

 characterized by having five ribs on each 

 half of the fruit, three on the back smaller 



; than the two at the sides, the latter being 

 larger and thicker, a character indicated 



! by the name, which is derived from two 



■ Greek words signifying' thick border.' The 

 species are natives of India, and are herba- 



i ceous plants, with hollow stems, and twice 

 i pinnate leaves, the leaflets of which are 

 i wedge-shaped, toothed at the end. [G. D.] 

 ! DASYMALIiA. A genus of small West 

 ' Australian bushes of the Myoporum family, 

 having their leaves and stems covered with 

 i dense white wool. The forked style and 

 bracted flower-stalks, together with the 

 woolly nature of the stems and leaves, are 

 its chief distinguishing features. Thefour- 

 angled stems are furnished with opposite 

 entire leaves, oblong obovate in form. In the 

 axils of these the flowers are found in little 

 I bundles or cymes shorter than the leaves. 

 The calyx is five-parted, and the purple 

 tubular corollas are widened at the top 

 and two-lipped, the upper lip two-lobed, 

 the lower three-lobed. In the inside of 

 the tube and near its base the four sta- 

 mens (two long and two short) are in- 

 serted. The ovary is densely hairy and 

 crowned with a filiform style forked at the 

 top ; when ripe it becomes a somewhat dry 

 four-celled berry with one seed in each 

 GelL Two species are known. [A. A. B.] 



DASYXEMA. A name once given to a 

 few South American trees of the lime-tree 

 family : they, however, belong to Sloaxea : 

 which see. [A. A. BJ 



DASYPHYLLUM. Flotovia. 



DASYPOGON. A genus referred to 

 Juncacece, in which it is distinguished by 

 its capsular one-celled fruit with basilar 

 ovules, and longitudinally dehiscent incum- 

 bent anthers with filaments thickened at 

 the apex. It comprises two undershrubs 

 from South Australia, with simple leafy 

 stems, and grass-like leaves rough at the 



margin ; flowers sessile in a gobular ter" 

 minal head. [J. T. S.] 



DASYSTEMON. A genus of Australian 

 herbs, covered with scaly pimples, and hav- 

 ing linear fleshy opposite leaves united at 

 their bases ; greenish yellow flowers ; a 

 calyx of three to seven leaf-like segments ; 

 corolla of three to seven petals rolled un- 

 der at the point, and slightly united at the 

 base ; stamens three to seven inserted on 

 to the calyx round the three to five 

 ovaries. The filaments are thick, hence the 

 name of the genus 'thick-stamen.' It is 

 included among the Crassulacece. B. caly- 

 cinns is occasionally grown as a green- 

 house plant in this country. [M. T. M.] 



DATE. Phoenix dactylifera. —, WILD. 

 P. sylvestris. 



DATISCACE.E. (Batiscads.) A natural 

 order of dicotyledonous plants included in 

 the sub-class Monochlamydece, and referred 

 byLindleytothe cucurbital alliance. Herbs 

 or trees with alternate leaves having no sti- 

 pules; some flowers have stamens only, 

 others have pistils only ; the corollais want- 

 ing ; the calyx or perianth adheres to the 

 ovary,and is divided into three or four parts; 

 stamens three to seven ; ovary one-celled, 

 with three or four many-seeded parietal 

 placentas. Fruit a one-celled capsule, 

 opening at the top ; seeds having a reti- 

 culated skin, and a cup-like swelling at 

 one end; there is no separate albumen. 

 The plants consist of few species, which 

 are scattered over North America, north- 

 ern India, Siberia, the Indian Archipelago, 

 and the south-eastern part of Europe. 

 They have bitter and purgative qualities. It 

 is said that the ovary of Batisca canndbina 

 can produce perfect seeds without the ap- 

 plication of pollen to the pistil. Tetrameles 

 Horsfleldii is a large tree of the order. 

 There are but three known genera, Batisca, 

 Tetrameles, and Tricerastes, and these corn- 

 prise but four species. [J. H. B.] 



DATISCA. A genus of plants typifying 

 the Batiscacece. The characters are : flow- 

 ers dioecious ; calyx five-parted in the sta- 

 minate flowers, three to five-toothed in 

 the pistillate flowers ; no corolla ; sta- 

 mens five to fifteen, collected in the 

 middle of the flower ; ovary united with 

 the calyx, inferior, one-celled, with three 

 to five parietal placentas ; styles three to 

 five. Fruit a one-celled capsule opening 

 by a round hole at the apex. Seeds numer- 

 ous, striated, with a cup-like covering at 

 the base. Annual herbaceous plants found 

 in Nepal and in Asia Minor. They have 

 unequally-pinnate alternate leaves, and 

 racemose bracteated greenish flowers. 

 There are two known species. [J. H. B.] 



DATLIER COMMUN. (Fr.) Phcenix 

 dactylifera. 



DATURA. A genus of Solanacece, or, ac- 

 cording to Mr. Miers, of Atropacece, the 

 species of which are eminently poisonous ; 

 while in small quantities they act as valu- 

 able remedial agents. They are known by 

 their tubular calyx, the upper part of 



