AN ENCYCLOPEDIA OF HORTICULTURE. 



479 



DIOSCOREACEJE. A natural order of twining 

 shrubs or herbs, found chiefly in tropical countries. 

 Flowers in spikes, small ; perianth of males six-cleft ; 

 lobes in two rows, herbaceous and adnate; stamens 

 six., inserted in the base of the perianth. Female flowers 

 with a six-cleft or six-partite perianth ; staminodes small, 

 three to six. Most of the Dioscoreas produce tubers 

 (known as Yams), which are used as food, in the same 

 way as potatoes. Dioscorea is the typical genus. The 

 order is represented in Britain by the Black Bryony. 

 Tamus communis. 



DIOSMA (from dtos, divine, and osme, smell; well- 

 bruised leaves have an exquisite smell). OBD. Rutacece. 

 A genus of about a dozen species of small greenhouse 

 Heath-like shrubs, all natives of South Africa. Flowers 

 white or reddish, terminal, sub-solitary or corymbose ; 

 calyx five-parted ; petals sessile, obovate, longer than 

 the calyx. Leaves alternate or opposite, linear-acute, 

 channelled, serrulated or ciliate, gland-dotted. Diosmas 

 may be very easily raised from cuttings, inserted in sandy 

 peat, covered with a bell glass, and placed in very 

 gentle heat. They will soon root, and may then be trans- 

 ferred singly into thumb pots, and afterwards, by suc- 

 cessive stages, into larger ones. It will be desirable to 

 keep the plants a little in shape by stopping the most 

 vigorous branches, thus causing a lateral growth. Diosmas 

 succeed in fibry peat and sand, and also in the same 

 compost, with the addition of a little fibrous loam. 



D. erlcoides (Heath-like).* JL white, with a tinge of red on the 

 upper surface, small, terminal, two or three together. February 

 to July. 1. crowded, trigonal, blunt, smooth, dotted, emitting a 

 strong penetrating smell when bruised, h. 1ft. to 3ft. 1756. 



FIG. 672. FLOWERING BRANCH OP DIOSMA VTLGARIS. 



D. vnlgaris (common). JL white, tinged with blue ; corymbs 



terminal, few-flowered. May. L scattered, linear, pointed, long, 



smooth, glandular, spreading, fringed. A. 1ft to 3ft See 



Fig. 672. (B. M. 2332, under name of D. erieoidet.) 



The other species are rarely seen in cultivation. 



DIOSPYROS (the old Greek name used by Theo- 



phrastus, from dios, divine, and puros, wheat; literally 



celestial food). Date Plum. OBD. Ebenacece. A genus of 



about 150 species of stove, greenhouse, or hardy trees and 



shrubs, represented in nearly all temperate and tropical 



regions. Flowers inconspicuous, polygamous, axillary. 



Leaves simple, alternate, entire, exstipulate. The green- 



Diospyroa continued. 



house species are ornamental, and thrive under ordinary 

 treatment; they are propagated by cuttings of half- 

 ripened shoots. Those requiring stove heat strike best 

 from ripened shoots, made during April or May, placed 

 in sand, and in a brisk bottom heat. The hardy species 

 may be increased by seeds. 



D. Ebenns. Ebony. /. white ; male ones Bub-racemose ; herma- 

 phrodite ones solitary. L bifarious, ovate-lanoeolate or oblong, 

 acuminated, glabrous, h. 30ft. to 40ft 1792. Store. (B. F. S. 6?) 



FIG. 673. FRUIT AJJD LEAVES OP DIOSPYROS KAKI. 



D. KaU (Kaki).* rf. whitish-green ; i 

 flowered, fr. yellow when ripe, glc 

 small orange, abounding in yellow, fl 



D. M""* 11 (Mazel's). 

 November. L elliptic-ovate or "sub-cordate, 'deciduous.' 



male peduncles usually three- 

 lobose, eight-celled, sire of a 



1 orange, abounding in yellow, fleshy, edible palp ; it is toler- 

 ably pleasant 1. bifarious, ovate-elliptic, acuminated, elliptic- 

 oblong or obovate, cordate at the base, downy on both surfaces. 

 Branches tomentose. h. 12ft. to 20ft China, 1789. Hardy in 

 South of England and Channel Islands, Ac. See Kig. 673. The 

 variety eogtata (G. C. n. s., iv. 777) is so named in consequence of 

 the depressed lines or ribs that mark the surface of the fruit from 

 the apex down towards the enlarged persistent four-lobed calyx 

 at the base. The name of Date Plum is, perhaps, more frequently 

 used for this species than for any of the others. 



D. Lotus.* European Lotus, or common Date Plum. /. reddish 

 white, small. July. fr. yellow when ripe, sweet with astringency, 

 size of a cherry. /. oblong, acuminate, of a beautiful dark glossy 

 green above ; when mature, and ^exposed to the air, they assume 

 a purplish hue beneath ; they do not change colour in autumn, 

 but drop off simultaneously with the first attack of sharp frost 

 A. 20ft to 30ft South Europe, Orient, 1596. Hardy. 



fr. orange-red, large, spherical, ripe in 

 ovate or sub-cordate, deciduous. Japan, 

 1874. (R.H.1874/70.) 

 D. virglnlana (Virginian).* Persimmon ; Virginian Date Plum. 

 fl. pale yellow. July. Jr. golden-yellow, size and form of a 

 "common Plum. I. ovate-oblong, acuminated, glabrous, shining 

 above, and paler beneath, reticulately veined ; petioles short and 

 curved, and, as well as the branchlets, downy, h. 20ft to 30ft 

 North America, 1629. Hardy. 



DIOTIS (from dw, two, and out, otot, an ear ; alluding 

 to the ear-like lobes of the corolla). Cotton Weed. OBD. 

 Composite. A very ornamental hardy perennial, with a 

 white and cottony aspect. It forms an excellent edging 

 or rockery plant, and is increased by cuttings or seeds. 

 D. candldissima (whitest). A synonym of D. maritima. 

 D. maritima (sea).* JL-headt yellow, sub-globose, discoid, i. 

 alternate, oblong, entire or toothed, densely covered with white 

 felted wool. Rootstock creeping, woody. A. 6in. to 1ft South 

 of England (rare), shores f i fltaiTMMn and the Canaries. 

 SYN. D. candiditrima. (Sy. En. B. 725.) 



DIPCADI (derivation obscure). STNB. Polemannia, 

 Tricharit, Uropetalum, and Zwxagnia. OBD. Litiace*. 

 A genus of pretty hardy and half-hardy bulbs, allied 

 to Oaltonia. There are about a score of species, 

 natives of South Europe, tropical and Southern 



