590 



BOTANY 



yellow flowers render them conspicuous in various situations and at all periods of 

 the year. The nectaries, which are borne on the receptacle at the base of tin- 

 stamens, also show that the flowers are entomoplulou.s. The family includes a 

 number of economic plants. 



1. Siliquosae dehiscentes : Cheiranthus Cheiri, the Wallflower (Figs. 612 A, 

 614 A). Matthiola, the Stock. Numerous species of Brassica have been long in cul- 

 tivation : B. oleracca, the Wild Cabbage, in its various forms (a) sylvcstris, which 

 occurs on the coasts of Northern Europe and is to be regarded as tin- wild form ; (b) 



acephala, Borecole or Kale ; 

 (c) gonglyodcs, Turnip- 

 rooted Cabbage ; (d) gem in i- 

 fera, Brussels Sprouts; () 

 bauda, Savoys; (f)capitata, 

 the Cabbage ; (</) Boti-ijtix, 

 Cauliflower and Broccoli. 

 Brassica, campesMs, witli 

 the cultivated forms (a) 

 annua, (b) oleifera, (c} //</'- 

 fera. Brassica napus, tlie 

 Turnip (a) annua, (b) olei- 

 fera, (c) napibrassica. 

 Brassica nigra, Black Mus 

 tard (Figs. 613-616), an 

 annual plant derived from 

 the eastern Mediterranean 

 region, was cultivated even 

 i n ancient times. The radical 

 leaves are long-stalked and 

 lyratc with rounded termi- 

 nal lobes ; on ascending 

 the copiously branched 

 stem they become lanceolate 

 and gradually smaller. The 

 plant is glabrous except for 

 .some bristly hairs on the 

 upper surface of the leaf. 

 Inflorescence a raceme ; tin- 

 bright yellow flowers stand 

 out from the main axis, while 

 the developing fruits an- 

 erect and applied to the 

 axis. The mature fruits have a short beak ; the slightly convex valves are keeled 

 and traversed by a well-marked midrib. Seeds spherical. ,S'//i//^/s nibn, White 

 Mustard, is a hairy .plant, distinguishable from the Black Mustard by the long 

 broadly-beaked fruits, the valves of which bear coarse bristly hairs. The fruits 

 project from the axis of the inflorescence. The seeds are yellowish-white and twice 

 as large as those of Brassica nigra. 



2. Siliquosae lomentaceae : Crambe (Fig. 612 E), with the lower portion of the 

 siliqua sterile, and Cakile are thick-leaved, strand plants. J'tijtliaiiits set tens, the 

 Radish. 



3. Siliculosae dehiscentes latiscptae : Vesicaria, Aubrietia, Draba, Lunaria, 



KM;. r,i7. Cupixiris spinosa. Flowering branch and a young 

 fruit borne on the gynophore. (J nat. si/c.) 



