268 



SYSTEMATIC BOTANY. 



, &c. The floral formula is S 5 P5 A 5+5 G 5. This Order 

 is nearly related to the Saxifragacese, especially by the genera with 

 capsular fruit ; and on the other hand to Paronychiaceae and Caryo- 

 phyllacece. They are remarkable for their succulent foliage, possessed 

 of a power of subsisting almost entirely on atmospheric elements, and 

 resisting obstinately the influence of heat and drought. They are ex- 

 ceedingly tenacious of life ; and Bryophyllum is celebrated for the aptitude 

 of its leaves to produce adventitious buds when separated and placed in 

 favourable circumstances. The symmetrical construction of the flowers 

 is likewise interesting to the botanist, and has been dwelt on in the 

 Morphological Part of this work. The Houseleek, Sempervivum tectorum, 

 occasionally produces monstrous anthers, with ovules in place of pollen. 



Distribution. Generally found in extratropical regions, in very dry 

 situations, and especially abundant at the Cape of Good Hope. 



Qualities and Uses. Their properties are mostly unimportant. Sedum 

 acre, the common yellow Biting Stone-crop of our walls, is so called from 

 its acridity, and is said to be emetic and purgative. Some are eaten ; 

 others used as refrigerants. Cotyledon Umbilicus has been used in epi- 

 lepsy. 



PARONYCHIACEAE OB ILLECEBPtACE^E are herbs or shrubs 

 with mostly opposite leaves and often scarious stipules, minute flowers, 

 with 5- or more, rarely 3- or 4-rnerous calyx ; petals small or absent ; 

 stamens on the calyx, 1-10 ; ovary 1-, rarely 3-celled ; ovules numerous 

 on a free central placenta, or solitary on a long funiculus from the base of 

 the ovary. Seeds perispermic ; embryo curved. 



ILLUSTRATIVE GENERA. 



Suborder 1. PARONYCHIEJS. With 

 scarious stipules ; stamens superposed 

 to the sepals. 



Paronychia, Juss. 

 Illecebrum, Gtertn.f. 

 Spergula, L. 



Subord. 2. SCLERANTHEJE. With- 

 out stipules ; calyx with an indurated 

 tube petals none ; stamens super- 

 posed to the sepals. 

 Scleranthus, L. 



SuborderS. MOLLUGINEJE. Sta- 

 mcns alternate with the sepals when 

 equal; if fewer ', alternate with the 

 carpels. 



Mollugo, L. 



Affinities, &c. This Order consists of upwards of a hundred species, and 

 may be regarded as a degeneration of Caryophyllacese, from which they 

 differ in the possession of stipules, the thin petals &c. forming a transi- 

 tion to the apetalous Chenopodiaceae and Amaranthacese. They are also 

 nearly related to Portulacacere, differing from some of the genera of that 

 Order only by the position of the stamens opposite the sepals. Some of 

 them are succulent, like the Crassulaceae, but are distinguished by the 

 structure of the ovary. By Bentham and Hooker they are included in the 

 Chenopodal cohort of the Apetala?. They are mostly valueless weeds, 

 abounding in barren sandy tracts throughout the temperate regions of the 

 globe. 



