306 



NATURAL HISTORY OF PLANTS. 



fleshy, as is most frequently the case in this order. The leaves are 

 alternate or opposite, exstipulate, succulent, cylindrical (fig. 332) or 

 flat (33 1), 1 entire or more rarely dentate or incised. The flowers 2 are 



Sedum acre. 



Fig. 333. 

 Flower (f). 



^ & <%, 



Fig. 334. 

 Diagram. 



Fig. 335. 

 Fruit (f). 



Sedum acre. 



sometimes solitary axillary, but oftener form regular or irregular 3 and 

 unilateral cymes (fig. 332). All the cold and temperate regions of 



the Old World abound in species ; they 

 are less numerous in America. 



S. pusillum? from Carolina, has been pro- 

 posed as the type of a genus Diamorp/ia, 5 

 because its carpels, usually four in number, 

 are slightly united towards the base. 6 We 

 shall place this small plant in a distinct 

 section because its follicles open down the 

 back. . 



Triactina verticittala, 1 a small Himalayan 

 herb, has the habit and vegetative charac- 

 ters of many Seclums. It differs slightly therefrom in the following 



Fig. 336. 

 Seed (L ). 



Fig. 337. 

 Long. sect, of seed. 



1 As a rule in the section Anacampseros (T., 

 Inst., 264 j — Haw., %». PI. Succ, 111, nee 

 Sims), which has turgid carpels and flat leaves. 



2 White, pink, violet, or bluish, but more 

 frequently yellow. 



a Owing to the flowers being carried up, or, as 

 some express it, the pedicels adhering to or 

 fused with the axes of the next degree. (See 

 Payee, Mem. de Bot., 117, 118, 121, figs. 188, 

 191.) 



4 Michx., Fl. Bor.-Amer., i. 276. — Tillaa 

 cymosa Nutt., Gen. Avier., i. 110. 



5 Nutt., Gen. Amer., i. 293. — DC, Prodr., 

 iii. 414 ; Mem., ii. 42, t. 1, fig. 9. — Endl., Gen., 

 n. 4624. — Tobb. & Geat, Fl. N.-Amer., i. 

 561.— Chapm., Fl. S. Unit. States, 150. 



6 Or rather their bases are inserted together 

 nearly vertically on a somewhat elongated re- 

 ceptacle. This occurs in a lesser degree in several 

 indigenous Sednms. Hence the inner edge of 

 the carpels becomes nearly horizontal and supe- 

 rior. 



7 Hook. f. & Thoais., in Journ. Linn. Soc, 

 ii. 90, 103— B. H., Gen., 6G1, n. 14. 



