428 ROSACEiE. Sanguisorca. 



tliin and brown. Embryo straight ; the radicle towards llie base ol" the calyx : 

 albumen none." Nuttail. 



11. PURSHIA. DC. h) Linn, trans. 12, 2^.157 ; Hool: f. Bor.-Jm. 1. 



2^. 170, t. 58. 



Cal3^x tubular-infundibuliform, jtersisteni, fi-cleft at the siimiiiit ; the lobes 

 ovate, obtuse, sj)reading, imbricate in aestivation. Petals .5, o])ovatc, ungui- 

 eulate. Stamens 25, in a single series, inserted with the petals into the 

 throat of the calyx : filaments filiform : anthers roundisli. Ovary solitary 

 (2 ex R. Br. fide Hook.), free, slightly stipitate, with a single erect ovule, 

 attenuate into the subulate style : stigma lateral, extending nearly the 

 whole length of the style. Achenium oblong, attenuate at each end (glan- 

 dular-pubescent, as well as the calyx), coriaceo-membranaceous, striate, 

 crowned with the persistent glabrous style. Seed obovate : testa merabrana- 

 ceous, separated from the inner coat (albumen, Hook.) by a layer of deep 

 purple, resin-like, intensely bitter, granulated matter. Cotyledons broadly 

 oval, flat. — A shrub, with erect branches and numerous very short branch- 

 lets : buds scaly. Leaves very small, crowded and fascicled, cuneiform, 

 subsessile, 2-^-toothed at the apex, tomentose-canescent beneath. Stipules 

 minute, triangular. Flowers subsessile, solitary or crowded in the fascicles 

 of leaves : petals j^ellow ? 



' ' P. tridenlata (DC. ! 1. c.) — Tigarea tridcntata, Pursli. ! fl. 1. p. 33, 

 t. 15. 



Plains of the Rocky Mountains, principally on the western slopes, and on 

 the Oregon, Lewis ! Douglas ! Nuttail ! On the Flat-Head River, Mr. 

 Wyeth! " Almost the only shrub to be seen through an immense tract of 

 barren sandy soil from the head-waters of the Missouri to the Falls of the 

 Columbia, and from 38° to 48° of north latitude." Douglas, in Hook. I. c. 

 " Not prevalent or abundant as far south as lat. 42"=," Nuttail. — We have 

 never seen more than a single carpel ; and this is to all appearance indehis- 

 cent ; although DeCandolle describes it as opening by a longitudinal fissure. 



Series 2. Seed attached next to the insertion of the style, either 

 ascending or suspended. Radicle always superior. 



Subtribe 3. Sanguisorbe^. — Calyx-tube mostly indurated and contract- 

 ed at the mouth ; the segments valvate or rarely imbricate in aestivation. 

 Petals often wanting. Stamens few or definite (1-15, rarely more, as in 

 Poterium). Carpels 1-2, or rarely 3-4, dry : styles terminal or lateral : 

 stigma often plumose. Seed suspended, very rarely ascending. Radicle 

 superior. — Herbs or sometimes shrubby plants. Flowers occasionally poly- 

 gamous or dia^cious. 



22. SANGUISORBA. Linn. ; Lam. ill t. 85. 



Flowers perfect, or rarely polygamous. Tube of the calyx quadrangu- 

 lar, 2-3-bracteolate ; the limb 4-parted. Petals none. Stamens 4, oppo- 



