GROUP V. ANGIOSPERXLE ; DICOTYLEDON ES. 



523 



Fig. 330,-Flower of Cheno- 

 podium (enlaiged) ; fc peri- 

 anth ; a stamens ; / ovary ; 

 n stigma. 



Stamens typically equal in number to and superposed on the 



usually four (2 + 2) or five (*-) free or connate sepaloid perianth 



leaves for the same reason as in the 



Urticales (p. 514) (Fig. 336). Ovary 



usually medially dimerous and unilocular, 



with a single campylotropous, erect or 



horizontal, basal ovule : seed contains 



perisperm, but no endosperm. Stipules 



wanting. 



Clienopodium album, the Goose-foot, and (.'. 

 Bonus ffenricus, the All-good, are common 

 weeds on garden-ground and waste land. 

 Spinacia oleracea is Spinach, cultivated as a vegetable. Beta vnlgaris is 

 cultivated under the var. Cicla (Mangold) ; B. altissima is the species used 

 in the manufacture of sugar, and B. rubra is the red Beetroot ; B. mari- 

 tima is the wild Beet. Salsola, the Salt-wort, and its allies, Suseda, the 

 Sea-blite, and Salicornia, the Marsh-Samphire or Glass-wort, with fleshy 

 stems and leaves, are conspicuous in the vegetation of the sea-shore. 

 Atriplex, the Orache, is the other British genus. 



Order 2. POLYGONACELE. The flowers have a simple 4, 5, or 

 6-leaved perianth which 

 may be either sepaloid 

 or petaloid, and usually 

 the same number of su- 

 perposed stamens ; but 

 occasionally the stamens 

 are more numerous or 

 some of them are sup- 

 pressed. Ovary usually 

 trimerous, unilocular, 

 with a single basal ortho- 

 tropous ovule ; the fruit 

 is frequently more or less 

 enveloped by the persist- 

 ent perianth. The leaves 

 have well-developed 

 sheaths (Fig. 337 A v} and 

 connate stipules forming 

 an ocrea (Fig. 337 A o : 

 see p. 31) which embraces 

 the stem for some distance 

 above the leaf -sheath. 



Fio. 337.- A Portion of the stem () of Pulygonum, 

 with a leaf (b), its sheath (r), and the ocres (o) (nat. 

 size). B Flower of Rheum; fc external, c internal 

 perianth-whorl ; a the stamen*. C Fruit of Rumex, 

 enclosed by the inner whorl of the perianth ; t base of 

 one of the perianth -leaves; fc external rerianth-leaves, 

 D Fruit of Rheum (/); fc outer, c inmr perianth-whorl 

 (enlarged). 



