344 



CRASSULACE^E. 



[Hypogynous Exogens; 



Order CXX. CRASSULACEjE.— House-leeks. 



Semnervivje Juss. Gen. 207. (1789).— Succulents. Vent. Tabl. 3. 271. (1799).— Crassul<e, Jim. Diet, det 



Sc Nat. 11. 369. (1818).— Crassulaces, DC. Bull. Philom. n. 49. p. 1. (1801; ; PI. Fr. cd. 3. v. 4. p. 



271. (180FI ; Mimoire (1828) ; Prodr. 3. 381. (1828) ; Endl. Gen. clix.; Meun. p. 134— Sedece, 



Sprenp. 

 Diagnosis.— Violal Exogens, with polypetalous or monopetalous flowers, a many-leaved 

 calyx, hypogynous petals, and follicular apocarpous fruit. 

 Succulent herbs or shrubs. Leaves entire or pinnatifid ; stipules none. Flowers 

 usually in cymes, sessile, often arranged ou one side only, along the divisions of the 

 cymes. Sepals from 

 .°. to 20, more or less 

 united at the base. 

 Petals inserted in 

 the bottom of the 

 calyx, either dis- 

 tinct or cohering in 

 a monopetalous co- 

 rolla. Stamens in- 

 serted with the pe- 

 tals, either equal 

 to them in number 

 and alternate with 

 them, or twice as 

 many, those oppo- 

 site the petals being 

 shortest, and arriv- 

 ing at perfection 

 after the others ; 

 filaments distinct, 

 subulate ; anthers 

 of 2 cells, bursting 

 lengthwise. Hypo- 

 gynous scales seve- 

 ral, 1 at the base of 

 each carpel, some- 

 times obsolete. Car- 

 pels of the same 

 number as the pe- 

 tals, opposite to 

 which they are 

 placed around an 

 imaginary axis, 1 - 



celled, tapering into stigmas, sometimes consolidated ; 

 styles continuous with the ovaries ; ovules sutural, 00, 

 or definite in number, horizontal or pendulous, anatro- 

 pal. Fruit consisting of several follicles, opening by 

 the suture, or collected into a capsule of several cells 

 opening at the back. Seeds attached to the margins of 

 the suture, variable in number ; embryo straight, in the 

 axis of fleshy albumen, with the radicle pointing to the hilum. 



All these plants are remarkable for the succulent nature of their stems and leaves, in 

 which they resemble many other and very different Orders. De Candolle suggests that 

 their real affinity is with Saxifrages through Penthorum, and with Knotworts (Illecebraceaj) 

 through Tilkea. In both those Orders the hypogynous scales of Houseleeks are wanting. 



Fig. CCXXX VL- Sedum acre. 



Fig. CCXXXVri.— 1. its flower ; 2. its seed cut open. 



