370 NATURAL HISTORY OF PLANTS. 



nate, stipulate, glandular, tripinnatisect, with very numerous 

 pinnules, glandular at their apices. The flowers, accompanied by- 

 glandular bracts, are collected into little cymes terminating the 

 branches. 



Pursliid} in habit and foliage nearly resembles Cowania, and not 

 certain species of PolcntiUas as is the case with Chamabatia ; still the 

 flowers are very like those of the last-named genus: the same 

 perianth, the same external capitate hairs, the same gj-na^ceum, with 

 its peculiar stigma formed of papilla? scattered over the everted 

 lips of the longitudinal groove of the style, the same ovule with 

 its ventral raphe and its interior dorsal micropyle. The sepals 

 and petals are imbricated in the bud, and the dry fruit, partly sur- 

 rounded by the hardened receptacle, contains a single seed with 

 thin albumen and an erect embryo whose radicle is inferior." But 

 the androceum of Purshia contains a far lower number of stamens ; 

 there are usually only from twenty to thirty ; the receptacle on 

 whose edges they are seated is much more elongated, like a cornet 

 or a narrow funnel; and the alternate leaves are small, serrate, 

 simple, and cuneiform, or tridentate, trifld, or even pinnatifid, with 

 two little adnate stipules at the base of the petiole. The only known 

 species,' which grows in the Eocky Mountains, has the appearance 

 of a little much-branched Cotoneaster. Its flowers are sessile, axillary 

 and terminal. 



Cercocarpiifi* (figs. 43G, 437) also consists of shrubs or under- 

 shrubs, in habit and foliage recalling certain species of Coicnnia. 

 The hermaphrodite flowers are constructed on the same general 

 type as in the two preceding genera ; the gynajceum, too, is reduced 

 to a single carpel whose ovary contains a single nearly basilar ovule, 

 with its raphe ventral. But there are no petals, and the receptacle 

 presents considerable modifications in the conformation of its 

 difl'erent j)arts. It is like a narrow vase, much elongated, and 



' DC, Trans. Linn. Soc, xii. 157 ; Prodr., ii. w exceptional in the Fraqarifit, would sct-m to 



641. — Hook., /'/. Jior.-Amer., i. 170, t. 58. — bring J*urshia near certain Spireea. 



LiNDL., Jiol. Reg., t. inn. — Kndl., Oen., n. ' P. tridrutata DC, loc. cit. — Tigarta tri- 



638(».— TouK. A (Jit., Ft. N. Amer., i. 428.— dentata Vvmn. 



B. H., Ufn., r,\7, n. Vl.— Titfarea I'itksii., Fl. * \\. U. K., iSor. Orn. el Spec, vi. 183, t. 



A'. Amer.,\. SM. t. 15 (nee Arm,.). Kiinzia 551».— DC, Prodr., ii. 58*1 — Tokk. & Ok.. /'/. 



Spkkn(}., Si/tt. I'etj., ii. tTn (mc Kkicii.). A. Aiitrr., i. 427.— Hook.. Iron., t. 322-324.— 



■•' The t.>U iH thick, hliukinh, and Hhininj,'. Km. I... (ien., n. 6381.— H. H., (?ri... 018. n. 40. 



and almost Hjx.npy intcnmlly. liKMiUM & — lirrtolonia Sk88. & Mo«;., ex DC, loe. rit. 



llooKUt n-niiirk that thin .in.Miiil/ati,,i, «)iich (not SrurNQ., nee lUuu.). 



