640 PART III. THE CLASSIFICATION OF PLANTS. 



Tribe 5. Pibesiece. Flowers epigynous, incompletely actinomorphic, penta- 

 merous : stamens five, opposite to the sepals ; carpels usually two, usually 

 median, sometimes lateral (Fig. 324B) : fruit a berry : leaves scattered : inflo- 

 rescence racemose. Shrubs. 



Several species of Ribes, the Currant, are cultivated : R. rubrum is the Bed 

 Currant ; R. nigrum, the Black Currant ; R. Grossularia, the Gooseberry : the 

 spines of the last species are developed from the pulvinus. 



Various species of Escallonia are cultivated as ornamental flowering shrubs. 



Order 2. CKASSULACE.S. Formula JCn, On, ) An + n, On, where 

 n = 3 30: flowers actinomorphic, perigynous or hypogynous, 

 with two (rarely one) whorls of stamens : gynaeceum, generally 

 completely apocarpous ; carpels opposite to the petals, with a scale 

 (disc), external to each carpel : ovules numerous, marginal : fruit 



St 



Fio. 411. Flower of Eibes (mng.): 8 FIG. 412. Flower of Sedum acre ( x 3). 



pedicel; fc calyx; c corolla ; st stamens ; 

 b disc ; g styles. 



a follicle : seed with endosperm : inflorescence usually cymose. 

 Plants with entire fleshy leaves, arranged spirally, often in rosettes. 



The genus Sedum has usually pentamerous flowers ; Sediim acre, the Stone- 

 crop, is common on walls and rocks ; S. Rhodiola has dioecious flowers (see 

 Fig. 318). S. Telephium, the Orpine and others are common. The genus Sem- 

 pervivumhas at least 6-merous flowers; S. Tectorum, the Houseleek, and other 

 species, as also species of Echeveria, Crassula, etc., are frequently cultivated. 

 Tilla3a has usually tetramerous flowers without the hypocarpellary scales. 



Order 3. CEPHALOTACE.S. Flowers apetalous, perigynous, 6- 

 merous : stamens in two whorls: gynseceum of six apocarpous 

 carpels, each containing a single basal ovule. 



This order consists of the Australian genus Cephalotus, with the single 

 species C. follicularis : the lower of the tuft of radical leaves are pitchered and 

 have lids. 



Order 4. PITTOSPORACE^]. Flowers hypogynous: stamens five, 

 antisepalous : carpels 2-5, ovary syncarpous, uni- or multi-locular, 



