^ 



DIOON 



lanugindsum, Hort., is a very woolly kind. Gt. 48, pp. 

 154, 155.— A variable species.' D. tonientosum, once sold 

 by Pitcher and Manda, was probably woollier than the 

 type. D. spinulosum. Dyer, differs mainly in having the 

 segments margined with small sharp points. Mex. A. P. 

 7:461. W. M. 



DIOSCOBfiA ( Di6scorides, the Greek naturalist). 

 Bioscoredeece. The type genus of a small family (of 



DIOSMA 



487 



about f 

 of 151) 

 them ! 



Lvs. broad, 



Tt contains upwards 



■i L'li.ii-. >i( IN. lu-rbaceous and 

 M-iit, ii-uall\ 1 r-iiii a large tuber- 

 •s ),,.:,rin- ml., r^ i,i tlie axils. 

 etted-veinrii, i- ii-Lm , iJimiate 

 or opposite, sometimes compnun h . Fls. 



small; calyx 0-parted, anthers 6 ; st . : i "iiled 



and calj-x adherent to it. Pr. a .l-w ihl 'I . i; -u :. . Seeds 

 winged. The great subterranean tuliiTs of some- species 

 are eaten in the manner of potatoes. Por an inquiry into 

 the prehistoric cultivation of Dioscoreas in America, 

 see Gray & Trumbull, Amer. Journ. Sci. 25:250. 



A. Sfems stronghj winged. 

 aiata, Linn. Pig. 714. Stem 4-winged or angular : Ivs. 

 opposite, cordate-oblong or cordate-ovate, with a deep, 

 basal sinus, glabrous, devoid of pellucid dots, 7- 

 nerved (sometimes 9-nerved ), with the outer pair united: 

 stamiuate spikes compound, special ones wborled, short, 

 flexuose : pistillate spikes simple : Hs. distant, anthers 

 subglobose, about as long as the filament : capsule 

 leathery, elliptical. India and the S. Sea Islands. 

 — Widely cult, in the tropics under many vernacular 

 names. Tubers reach a length of 6-8 ft., and some- 

 times weigh 100 lbs.; edible. The roots continue to 

 grow for years. Variable. 



Showing foliage ( 



small tuber. 



AA. Stems terete (cylindricul). 

 B. I/VS, plain green. 

 divaricata, Blanco. {D. Batatas, Vleene.). Yam. Chi- 

 nese Yam. Chinese Potato. Cinnamon Vine. Very tall 

 climbing (10-:J0 ft.), the Ivs. 7-9 ribbed, cordate-ovate 

 and shining, short-petioled, bearing small clusters of 

 cinnamon-scented white fls. in the axils: root tubers 



deep iu the ground, 2-3 ft. long, usually larger at the 

 lower end. Philippines. P.S. 10:971. R.H. 1854, p. 

 247, 451-2. — This is often grown in the tropics for its 

 edible tubers, which, however, are difficult to dig. In 

 this country the word Yam is commonly applied to a 

 tribe of sweet potatoes (see Sweet Potato). The Yam 

 is hardy. The root will remain in tlie tjniiind over 

 winter in New York, and sendup handsonn- t:ill, twining 

 shoots in the spring. The plant bears little tubers in 

 the leaf -axils, and these are usually planted to produce 

 the Cinnamon Vine; but it is not until the second year 

 that plants grown from these tubercles produce the 

 large or full grown Yams. A form with short and potato- 

 like tubers is D. VecaisneAna, Carr. (R.H. 1865:110). 



^ 



715 A r Potato— .«; 



shape ) These t 1 

 They aie palatal le 

 tubers are usuall} 

 villdsa Lmn Stei 



id te . 



bulb fera (X 4) 



1 I nerved 



II 18 49 - 



t tb ei) large 



■>tl 1 ze and 



1 several pounds 



flavor The root 



li tte 1 lootstocks 

 idte 9 11 ribbed 

 tb alt u te oppo 

 m nate i irooping 

 pie racen es cap 



so ue h t 1 ube ent or 1 vnj 



te or w boiled fls green b 1 

 panicles the pistillate m Iroop 



sules very strongly winge 1 — Oomm n in th ckets from 

 N Eng to Fla Perenn al Tw nmg 8 10 or even Id ft 

 Offered in the trade as a hardj bolder and art or plant. 

 BB. it's, variously marked and colored, at least beneath. 



discolor, Hort. Lvs. large, cordate-ovate, cuspidate, 

 with several shades of green, white-banded along the 

 midrib and purplish IteTieath; fls. greenish and incon- 

 spicuous: rent tnliereu^, s. AiHcr. Lowe 54. — Useful 

 for the eoiiserx :(Im!\ . su:::;estive of Cissus discolor. 



multicolor, Liml. ct Aiehe. Probably only a form of 

 the last: Ivs. vaiiou.sly iiiaiked and blotched and veined 

 with silvery white, red, green and salmon. S. Amer. 

 I.H. 18:53.— Very decorative glasshouse plant. 



Other species are cult, in the Gulf region. One, with 2- 

 winged stem and 3-lobed lvs, (tlie "Yampie"), is perhaps Z>. 

 tnbihn. I. inn. One with pricklycjiimlriral stems and opposite 





apical eul- 



ti\aleil ^]]e<'ies, and the name slit iiiM lie Wrepiieil — J'er Japanese 

 culti\ate(i species, see Georgeson,-\.'i. 1:;;mi, witii iilustr.itions. 

 L. H. B. 



DI6SMA (Greek, dijjiBeotJor). Butctcece. Small, ten- 

 der, heath-like shrubs from southwestern Africa. Of 

 the 228 species described, barely a dozen now remain in 

 this genus, the rest being mostly referred to allied 

 genera, especially Adenandra, Agathosma and Barosma. 

 Lvs. alternate or opposite, linear-acute, channeled, ser- 

 rulate or sometimes ciliate, glandular dotted: fls. white 

 or reddish, terminal, subsolitary or corymbose, pedicel- 

 late ; calyx 5-parted; hypogynous disk, 5-sinuate, 5- 

 plaited; petals 5; style short ; stigma capitate. Latest 

 monograph in Flora Capensis, vol. 1 (1859-60). -^^ jj_ 



Diosma ericoides is more or less well known in 

 America, and is put to various uses in floral decora- 

 tions, in spray, or branchlets cut to the required length, 

 and stuck in formal designs as a setting for other flow- 



