i .;'.* 



Geography. Natives of the temperate parts of North and South Ame- 

 rica. 



Properties. Unknown. 



Examples. Galax, Francoa. 



Obs. This order requires to be reconsidered. 



CXLVII. CRASSULACEiE. The House-leek Tribe. 



Semperviv*:, Juss. Gen. 207 (1789).— Succulent*, Vent Tabl. 3. 271. (179 1 *).— Crassul*:, 

 Juss. Dict.des Sc. Nat. 11. 369. (1818).— Crassulace-k, Dec. Bull. Philom. n. 49. p. 1. 

 (1801) ; Fl. Fr. ed 3. v. 4. p. 271. (1805) ; Memoirc (1828) ; Prodr. 3. 381. (1828) : LindL 

 Synops. 63. (1829).— Sede^e, Sprcng. 



Diagnosis. Succulent polypetalous dicotyledons, with definite perigynous 

 stamens, superior distinct ovaria surrounded at the base by hypogynous scales, 

 indefinite albuminous seeds, sepals in a single row, and exstipulate leaves. 



Anomalies. Penthorum is not succulent. This genus and Diamorpha 

 have the ovaria concrete. Some are monopetalous, particularly the genus Co- 

 tyledon. Petals and stamens often almost hypogynous. TiLtea has definite 

 ovules. 



Essential Character-.— Sepals from 3 to 20, more or less united at the base. Petals in- 

 serted in the bottom of the calyx, either distinct or cohering- in a monopetalous corolla. Sta- 

 mens inserted with the petals, either equal to them in number and alternate with them, or 

 twice as many, those opposite the petals being shortest, and arriving- at perfection after the 

 others ; filaments distinct, subulate; anthers of 2 cells, bursting lengthwise. Hypogynous 

 scales several, 1 at the base of each ovarium, sometimes obsolete. Ovaria of the same num- 

 ber as the petals, opposite to which they are placed around an imaginary axis, 1-celled, taper- 

 ing into stigmata. Fruit consisting of several follicles, opening by the suture in their face. 

 Seeds attached to the margins of the suture, variable in number ; embryo straight in the axis 

 of the albumen, with the radicle pointing to the hilum.— Succulent herbs or shrubs. Leave* 

 entire or pinnatifid ; stipulce none. Flowers usually in cymes, sessile, often arranged unila- 

 terally along the divisions of the cymes. 



Affinities. These are all remarkable for the succulent nature of their 

 stems and leaves, in which they resemble Cacteae, Portulacea-, and certain ge- 

 nera of Euphorbiacea?, Asclepiadea?., and Asphodeleee ; but this analogy goes 

 no further. Their real affinity is probably with Saxifrages?, through Pentho- 

 rum, and with Illecebrere through Tillaea, as Decandolle has remarked. In 

 both those orders the hypogynous scales of Crassulacese are wanting. Are 

 not these bodies analogous to the scales out of which the stamens of Zygo- 

 phyllese spring % If so, an unsuspected affinity exists between these orders. 

 Decandolle observes {Mdmoire, p. 5.) that there is no instance of a double 

 flower in the order, although this might have been expected from their analogy 

 in structure with Caryophyllea?. Sempervivum teclorum exhibits almost con- 

 stantly the singular phenomenon of anthers bearing ovules instead of pollen. 



Geography. It appears from Decandolle's researches, that of the 272 

 species of which the order consists, 133 are found at the Cape of Good Hope, 

 2 in South America beyond the tropics, 2 in the same country within the tropics, 

 none in the West Indies or the Mauritian Islands, 8 in Mexico, 7 in the United 

 States, 12 in Siberia, 18 in the Levant, 52 in Europe, 18 in the Canaries, 1 in 

 southern Africa beyond the limits of the Cape, 9 in Barbary, 3 in the East 

 Indies, 4 in China and Japan, and 2 in New Holland They are found in the 

 driest situations, where not a blade of grass nor a particle of moss can grow, 

 on naked rocks, old walls ; sandy hot plains, alternately exposed to the heaviest 



