350 



NATURAL HISTORY OF PLANTS. 



Sanguisorba (^Po(erium) polygama. 



certain species have only ten or twelve, or even five or six.' Thus 

 the diflerences formerly pointed out between these two genera 

 gradually disappear, and they become quite inseparable. 



Thus constituted, this generic group contains about fifteen species 

 found native in all the temperate and warm regions of the northern 



hemisphere,^ Nearly all are herba- 

 ceous and perennial ; one alone is 

 annual, and has been made the type 

 of a distinct genus under the 

 name of Poieridium? P. sp.inosimi* 

 is frutescent, and its aborted 

 branches are to some extent trans- 

 formed into spines. Its floral 

 receptacle becomes thicker and 

 fleshier than in the other species. Hence the generic name of Sar- 

 copoteriitm'' proposed for this species. 



The flowers of Polt/lepk^ have the receptacle and indefinite stamens 

 of Potcrhim. The calyx has from three to five leaves, slightly im- 

 bricated when young, but, as a rule, finally becoming valvate. The 

 carpels are usually solitary ; but this is not constant, some flowers 

 possessing two or three carpels ; they are in other respects those of 

 Poterium. The receptacle Ibrms a sac around them in the fruit, and 

 is marked by longitudinal projecting lines, here and there inter- 



Fio. 405. 

 Hermaphrodite flower. 



Fio. 406. 

 Heptandrous flower. 



' So too there are true Sanguisorhas whose 

 specific name iiulicatcs the general number of 

 stamens, sudi us S. dodecandra MouETT., dec- 

 andra Walt,., &c. These stamens are also 

 longer. In the i-p cies of the section or sub- 

 genus Poterium, such as P. Sanguisoiha h., 

 anculroides Dksf., &c., there are almost always 

 male flowers at the base of the spike, female 

 flowers at the a])ex,and between them a variable 

 number of completuly or incompletely herma- 

 phrodite flowers with ten or twelve stamens (fig. 

 40r>) or even only half a ilo/on (fig. Un]) ; they are 

 then shorter than in tlie male flowers. In the 

 hermaphrodite (lowers the gyna;ceuni may have 

 a ster.le «>v.iry, but the btyle and stigma are 

 pretty well developed. In many species, too, 

 the expauhion of the flowers la-gins as do- 

 scribed in tlie text. The fruit is the organ sub- 

 ject to the greatest variations in I'ulirium ; und 

 SpaCII, in founding sulxlivisions in this group, 

 has chiefly regarded the outer Murfucc of tlie in- 

 diisium, whetlier reticuliite, rugos4', nniriciit-e. 



warty, or veined, or more or leas marginate or 

 four-winged. 



■■' DC, Prodr., ii. 593-595.— Wai.p., Pep., 

 ii. 41; Ann., i. 282; iii. 855; iv. 665.— Dksf., 

 Fl. Athint., ii. 3K5, t. 251.— Tohh. & (Jr.. FI. 

 N. Anier., i. 428. — Spach, Peris. Gen. Pote- 

 rium, Ann. Sc. Nat., si^r. 3, v. 31. — tiREN. k 

 Ooi)i{.,/y. t/p /'/•.,!. 562.— A. (iRAY.-VrtM. of But., 

 ed. 5, 150.— CiiAPM., Fl. S. Unit. -States, 122.— 

 IIarv. iV SoND., Fl. Cap., ji. 25)2.— .MiQ., Mtts. 

 Luijd. Bat., iii. 38. — Tnw., Fnum. PI. Zryl., 

 1112.— A. Hr., App. llort. Berol. (ISC?), lo." 



'* Si'Ai II, Ann. Sc. Sat., ser. 3, v. 43 {San- 

 ijuisorbn annua ToKR. Si (iH., Fl. X. Atner., i. 

 A2\);— Poterium nnnuum NllT.). 



* L., Spec, 1411.— IK'.. Prodr., n. 1 (sect. 

 I^iopoterium). — SiiiTll.. Fl. (/rrrc, t. 913. 



* .^i-ACii, AiiH. Sc. Art/., loo. eit. 



« U. & I'AV., Prodr., Fl. Per. et Chil., 34, t. 

 15.— DC, Prodr., ii. 691.— K.nui.., Oen, n. 

 r,377.— H. H.. Urn., 623. n. 55. 



