58 cxix. POLYGONACE.E. (J. D. Hooker.) [Rheum. 



a plant inhabiting the lofty regions of East China bordering Tibet, which is probably 

 this or an allied species. 



6. OXVRXA, Hill. 



An erect herb, with stout rootstock. Leaves chiefly radical, orbicular- 

 cordate or reniform ; stipules broad, lax. Flowers in fpanicled racemes, 

 2-sexual. Sepals 4, 2 outer reflexed ; 2 inner larger, erect, appressed. 

 Stamens 6. Ovary compressed ; styles 2, short, stigmas fimbriate. Nut 

 biconvex, 2-winged. Embryo lateral, nearly straight, cotyledons linear- 

 oblong. 



O. digryna. Sill ; Boiss. FL Orient, iv. 1004 ; leaves cordate or reni- 

 form. 0. reniformis, Hook. Fl. Scot. Ill ; Meissn* in DC. Prodr. xiv. 1. 

 37 ; Engl. Bot. t. 910. 0. elatior, Br. in Wall. Cat. 1726 ; Meissn. in Wall. 

 PI. As. Rar. iii. 64, and in DC. I c. Royle III. PI. Him. 314; Hook. Ic. 

 PI. t. 483. 



ALPINE HIMALAYA; from Sikkim to Kashmir, alt. 10-14,000 ft. WESTEEN 

 TIBET, alt. 12-17-500 ft. DISTEIB. Mts. of Europe, N. Asia and America, Arctic 

 Regions. 



Glabrous, fleshy. Rootstock tufted, with many erect succulent stems 4-18 in. 

 high. Leaves radical, many, long-petioled, 1-4 in. diam., rarely 3-lobed or sub- 

 hastate, cauline 1-2 ; petiole sometimes 8 in. Racemes slender, lax-fld. ; pedicels 

 jointed in ^the middle, tip thickened. Outer sepals spreading or reflexed ; inner 

 spathulate, 3 5-nerved. Fruit - ^ in. diam., orbicular-cordate, wing membranous 

 veined top notched. A most agreeable salad, raw and cooked. Except in often 

 attaining a very large size (18 in. high), the Himalayan plant does not differ from 

 the European. 



7. RU1MEX, Linn. 



Perennial herbs, or annuals, rarely shrubby. Leaves various ; stipules 

 often disappearing with age. Flowers in axillary clusters or in whorls 

 arranged in simple or panicled racemes. Sepals 6 (rarely 4) ; outer un- 

 changed, inner enlarging entire or toothed, midrib or disk often enlarged or 

 tubercled. Stamens 6. Ovary 3-gonous ; styles 3, stigmas fimbriate. Nut 

 included in the usually enlarged inner sepals (valves) angles acute. Embryo 

 lateral, nearly straight ; cotyledons linear or oblong. Species described 

 about 100 (probably greatly exaggerated), in all temperate and some tropical 

 countries. 



I think that this genus wants revision and a very great reduction of species, when 

 most of the Indian ones will be referred to European, in the directions I have indicated 

 under each. 



Sect. I. Lapathum, Meissn. Flowers 2-sexual. Styles terminal. 

 Inner sepals (valves) coriaceous much enlarged in fruit. Leaves not 

 hastate. 



* Inner fruiting '-sepals quite entire, disk tumid or not. 



1. R. orientalis, BernL; Boiss. FL Orient, iv. 1009 ; tall, stout, 

 leaves elongate-oblong obtuse base cordate, racemes in an open lax or 

 thyrsoid dense panicle, whorls crowded, pedicels about equalling the fruiting 

 perianth, valves broadly orbicular-cordate obtuse reticulate quite entire with 

 or without a small tubercle. Meissn. in DC. Prodr. xiv. 1. 51. B. Dios- 

 coridis, Hayne Arnzeik. xiii. 5, t. 5. 



WESTEEN HIMALAYA; Kumaon to Kashmir, alt. 6-9000 ft., Falconer, &c. 



