PORTULAC ACE.E PARONYCHIACEjE. 419 



rlons plano-convex; radicle pointing to the hihun. Herbaceous or 

 somewhat shrubby plants, occasionally with stellate pubescence, having 

 alternate, exstipulate leaves, and frequently two glands at the apex of 

 the petiole. They are natives of the West Indies and South America. 

 They are not put to any important use. Lindley gives 2 genera, in- 

 cluding 60 species. Examples Turnera, Piriqueta. 



878. Order 88. Portuiacaceae, the Purslane Family. (Polypet. 

 Perigyn.) Sepals 2, cohering at the base. Petals usually 5, rarely 

 wanting, distinct or cohering at the base, sometimes hypogynous. 

 Stamens usually perigynous, variable in number, all fertile, sometimes 

 opposite the petals ; filaments distinct ; anthers versatile, bilocular, 

 with longitudinal dehiscence. Ovary free or partially adherent, 1- 

 celled, formed by 3 united carpels ; style single or ; stigmas several. 

 Fruit capsular, 1 -celled, opening by circumscissile dehiscence, or by 3 

 valves, occasionally monospermous and indehiscent. Seeds numerous or 

 definite, or solitary, attached to a central placenta ; albumen farina- 

 ceous; embryo peripherical; radicle long. Succulent shrubs or herbs, 

 with alternate, seldom opposite, entire, exstipulate leaves, often having 

 hairs in their axils. They are found in various parts of the world, 

 chiefly, however, in South America and at the Cape of Good Hope. 

 They have a great affinity to Caryophyllacea3, from which they are 

 chiefly distinguished by their bisepalous calyx, perigynous stamens, 

 and transversely dehiscent capsule. Lindley places this and the suc- 

 ceeding order among hypogynous Exogens, next to Caryophyllacese. 

 The plants belonging to the order have few properties of importance. 

 They are insipid and destitute of odour. Portulaca oleracea, common 

 Purslane, is used as a potherb. The tuberous roots of Claytonia 

 tuber osa, a Siberian plant, are eaten ; and those of Melloca ( Ullucus) 

 tuberosa, a native of Peru, have been recommended as a substitute for 

 the potato. There are 12 known genera, and 184 species. Examples 

 Portulaca, Talinum, Calandrinia, Claytonia, Montia. 



879. Order 89. Paronychiacese, the Knotwort Family. (Polypet. 

 Perigyn.} Sepals 4-5, distinct or cohering. Petals perigynous, be- 

 tween the divisions of the calyx, usually inconspicuous, sometimes 0. 

 Stamens usually perigynous, sometimes hypogynous, opposite to the 

 sepals when equal to them hi number, some of them occasionally 

 wanting ; filaments distinct, rarely united ; anthers bilocular. Ovary 

 superior, with one or more ovules ; styles 2-3, distinct or combined. 

 Fruit unilocular, either a utricle covered by the calyx, or a 3-valved 

 capsule. Seeds either numerous, attached to a free central placenta, 

 or solitary and pendulous from a long funiculus arising from the base 

 of the fruit. Embryo more or less curved, lying on one side of the 

 farinaceous albumen, or surrounding it. Herbaceous or somewhat 

 shrubby plants, with opposite or alternate, sometimes setaceous and 

 clustered leaves, which are either exstipulate or have scarious stipules. 



