696 POYYGONACE^. (BUCKWHEAT FAMILY.) 



Oclireae membranous, short-bilobed. Leaves usually minute, soon 

 deciduous. Flowers few, clustered in dhe axils of the oclireae, on 

 jointed pedicels. 



1. C. comosum, L'her. 5 ^osah. Risu. And. 3 to 5, glabrous; 

 branches white, tortuous. Leaves hardly .002 long, subulate, adnate 

 to ochvem. Akene ovate, bristles in 12-16 rows, branching, soft^ dilated 

 at base, more or less joined into 4, short wings — April — Syria; Ghor- 

 e-^Safieh to Sinai and Egypt. 



2. C. poIygonoi€lc§j L. ^ Z to 5, glabrous; branches 

 slender. Leaves .006 to .01 long, subulate, free from ocJircce, soon 

 deciduous. Akene oblong, bristfes rigid, branching, dilated at base, 

 more or less joined in short wings — Spring — Southern and eastern 

 Deserts (Tristram). 



2. RHEUM, L. Rhubarb. RiUs. 



Flowers perfect. Perigonium herbaceous, 6-parted, marcescent, 

 with nearly equal lobes. Stamens 9, inserted at bottom of calyx. 

 Ovary free, triquetrous, styles 3, short, spreading, stigmas entire, dis- 

 coid. Akene samaroid, 3-winged-angled, much longer than appressed 

 perigonium. Seed erect, embryo straight in axis of mealy albumen, 

 radicle short, superior — Coarse herbs, with a thick rhizome, thick, 

 short, annual stems, and broad, palminerved leaves. 



R. Ril>c§, Gronov. 2| Puhds. 1 or more, stem leafy below, 

 leafless above, ending in a broad, clustered panicle. Leaves glauces- 

 cent, leathery, cordate-orbicular to reniform, .2 to. 8 broad, denticulate, 

 coarse-nerved, nerves papillose below. Pedicels clustered, filiform; 

 akene crimson, somewhat fleshy, cordate-ovate, .01 to .015 long, wings 

 2-3 times as broad as seed — May — Moab; subalpiue and alpine Leb- 

 anon; Amanus, and northward, and eastward. 



3. OXYRIA, Hill. Mouis^tain- Sorrel. 



Flowers perfect. Perigonium herbaceous, 4-parted, marcescent, 

 the inner pair of sepals broader, at length appressed to akene, the 

 outer pair reflexed. Stamens 6, a pair opposite each outer sepal, and 

 a single one opposite each inner. Ovary compressed, stigmas two, 

 nearly sessile, penicillate. Akene lenticular, membranous, surrounded 

 by a broad, translucent wing. Seed compressed, erect. Embryo in 

 axis of mealy albijmen, radicle straight, superior — Tender, low, 

 alpine herbs. 



O. digyua, L, 11 .01 to .035; neck much branched, scaly from 

 old ochregg and petioles; stems nearly leafless, ending in a simple 

 raceme or meagre panicle. Leaves cordate-orbicular to reniform, .01 

 to .025 broad, long-petioled, sometimes obsoletely 3-lobed. Pedicels 

 filiform, jointed about middle, somewhat longer than fruit; akene 

 orbicular, cordate at base, .003 long, more or less incised at tip, wing 

 purple, transversely veined, as broad as seed or broader — Late sum- 

 mer — Alpine Lebanon. 



4. EMEX, Neck. Emex. 



Flower moncecious - polygamous. Staminate. Perigonium her- 

 baceous, 3-6-parted, lobes equal, spreading. Stamen]? 4-6. Pistillate. 



