320 NATURAL HISTORY OF PLANTS. 



GENERA. 



1. Seduni T. — Flowers regular, 5-merous (or more rarely 4, 6, 7- 

 merous) hermaphrodite or polygamous ; receptacle usually narrow. 

 Sepals free or connate at base, usually small, thick, valvate. Petals 

 free, imbricate or twisted. Stamens twice as numerous as petals, 

 equal, usually slightly perigynous ; filaments all free, or shorter ones 

 adnate to base of petals ; anthers sub-2-dymous, introrsely or latterly 

 2-rimose. Scales as numerous as petals, inserted external to base of 

 carpels, entire or 2-fid. Carpels 5 (more rarely 4, 6, 7), free or more 

 rarely connate at base, 1 -celled, tapering above into style ; apex stig- 

 matose inside; ovales oc, more rarely few or 1, oblique anatropous, 

 inserted on ventral angle. Follicles 4-7 finally gaping internally or ex- 

 ternally; seeds l-oo, often dotted; embryo exalbuminous (or slightly 

 albuminous) ; cotyledons fleshy ; radicle cylindrical. — Undershrubs or 

 far oftener herbs, perennial or rarely annual, fleshy, glabrous or 

 pubescent ; leaves alternate opposite or verticillate, exstipulate ; 

 flowers cymose ; cymes regular, or by abortion uniparous, sometimes 

 few-flowered {Temperate and cold Regions of Northern Hemisphere, South 

 America). See p. 304. 



2 ? Triactina Hook. p. & Thoms. — Flowers nearly of Sedum, 4, 5- 

 merous. Scales and carpels (of Sedum) 3, connate at base. Follicles 3 ? 

 many-seeded. — An annual (?) herb ; habit of Sedum ; leaves (of 

 Sedum) alternate opposite or verticillate, rather fleshy, entire ; flowers 

 in lax leafy racemes (Temperate Himalayas). See p. 306. 



3. Sempervivum L. — Flowers nearly (of Sedum), 6-co-merous, 

 more rarely 5-merous. Sepals narrow, free or connate at base. 

 Petals as many, alternate, free or connate at base, imbricate. Stamens 

 co, usually twice as numerous as petals (very rarely of same number) ; 

 filaments free ; usually slightly perigynous at base, anthers ovate or 

 2-dymous. Scales go, superposed to carpels, simple or 2-fid, sometimes 

 connate in pairs, more rarely 0, or more or less stipitate petaloid 

 (Monanthes). Carpels (of Sedum) as numerous as petals and superposed 

 to them ; ovules co. Follicles co (of Sedu?n); co-seeded. Undershrubs or 



