CRA SS ULA CEAE. 473 



Family 2. CRASSULACEAE DC. 



Orpine Faintly. 



Herbs, or somevvh shrubby plants, mostly fleshy or succulent, with 

 cymose or rarely solitary regular or symmetrical flowers. Stipules none. 

 Calyx persistent, free from the ovary or ovaries, 4-5-cleft or4~5-parted in 

 our species. Petals equal in number to the calyx-lobes, distinct, or 

 slightly united at the base, usually persistent, rarely wanting. Stamens 

 of the same number or twice as many as the petals; anthers longitudi 

 nally dehiscent. Receptacle with a scale at the base of each carpel. Car- 

 pels equal in number to the sepals, distinct, or united below; styles sub- 

 ulate or filiform ; ovules numerous, arranged in 2 rows along the ventral 

 suture. Follicles i-celled, dehiscent along the ventral suture. Seeds 

 minute; endosperm fleshy; embryo terete; cotyledons short, obtuse. 

 About 15 genera and 500 species, of wide geographic distribution. 



Stamens of the same number as the sepals; minute herbs. 1. Tillaea. 

 Stamens twice as many as the sepals ; succulent herbs. 



Flowers 4-5-parted. 2. Sedum. 



Flowers 6-20-parted. 3. Sempervivum. 



1. TILLAEA L. 



Minute aquatic or mud-loving herbs, with opposite entire leaves and very 

 small flowers. Calyx 3-5-parted. Petals 3-5, distinct, or united at the base. 

 Carpels 3-5. distinct. Styles short, subulate. Ovules usually few. [Named 

 after Michael Angelo Tilli, 1653-1740, an Italian botanist.] About 20 species of 

 wide distribution. Besides the following, about 4 others occur in the western 

 States. 



1. Tillaea aquatica L. Pigmy-weed. (I. F. f. 1809.) Stem 1-8 cm. high, 

 glabrous. Leaves linear-oblong, entire, connate at the base, 4-6 mm. long; 

 flowers solitary, axillary, sessile or short-peduncled, I mm. broad; calyx-lobes, 

 petals, stamens and carpels 4, rarely 3; petals greenish, about twice the length of 

 the calyx-lobes; follicles ovoid, longer than the calyx-lobes, 8-io-seeded. Muddy 

 banks of streams, N. S. to Mass. and Md. Also in Europe. July-Sept. 



2. SEDUM L. 

 Fleshy mostly glabrous herbs, mainly with alternate, often imbricated leaves, 

 and perfect or dioecious flowers in terminal often 1-sided cymes. Calyx 4-5-lobed. 

 Petals 4-5, distinct. Stamens perigynous. the alternate ones usually attached to 

 the petals. Carpels 4-5, distinct, or united at the base; styles usually short; 

 ovules 00 . [Latin, to sit, from the lowly habit of these plants.] About 150 

 specie-, mostly natives of temperate and cold regions of the northern hemisphere. 

 Besides the following, about 20 others occur in western N. Am. 



Cyme regular, compound, the flowers not secund ; leaves broad, flat. 



Flowers dioecious, mostly 4-parted. 1. S. roseum. 



Flowers perfect, 5-parted. 



Petals purple ; plant somewhat glaucous ; petals twice as long as the sepals. 



2. S. Telephiiim. 

 Petals pink ; plant very glaucous ; petals 3-4 times as long as the sepals. 



3. S. telephiotdes. 

 Flowers secund along the branches of the cyme. 



Petals yellow. 



Leaves short, thick, ovate, densely imbricated. 4. S. acre. 



Leaves linear or terete, scattered on the stems. 



Annual ; petals little longer than the sepals. 5. S. Torreyi. 



Perennial ; petals twice as long as the sepals. 



Plant 0.7-1.5 dm. high; native, western. 6. S. stenopetalum. 



Plant 2-3 dm. high, introduced in a few places. 7. S. reflextim. 

 Petals purple or white. 



Leaves terete ; petals purple, pink, or white. 8. S. pulchellum. 



Leaves flat, spatulate or obovate ; petals white. 



Lower leaves verticillate in 3's. 9. S. ternatum. 



Leaves all alternate. 10. S. Aevii. 



