398 MANUAL OF BOTANY 



trative Genera : — Pedalium, Linn. ; Sesamum, Linn. There 

 are about 25 species. 



Projaerties and Uses. — Chiefly remarkable for their oily 



Order 207. Acanthaoe^, the Acanthus Order. — C haraoter. 

 Herbs or ahruhs. Leaves opposite or whorled, simple, exstipu- 

 late. Flowers irregular, bracteate. Calyx 4 — 5-partite, or 

 consisting of 4 — 5 sepals, persistent, much imbricate ; sometimes 

 obsolete. Corolla more or less 2-lipped. Stamens 2 or 4, in 

 the latter case didynamous. Ovary seated on a disc, 2-ceIled ; 

 placentas parietal, although extended to the axis ; style 1. 

 Fruit capsular, 2-ceUed, with a variable number of seeds in 

 each cell. Seeds hanging by hard cup-shaped or hooked pro- 

 jections of the placenta, without wings ; albumen none ; 

 cotyledons large and fleshy ; radicle inferior. 



Distribution am,d Numbers. — Chiefly tropical. Illustrative 

 Genera : — Acanthus, Tourn. ; Justicia, Nees. There are nearly 

 1,500 species. 



Properties and Uses. — Generally unimportant ; but several 

 species are mucilaginous and bitter. 



Cohort 4. — Lamiales. 



Order lOH. SelaginacbjE, the Selago Order. — Character. 

 Herbs or shrubs, with alternate exstipulate leaves. Flowers 

 irregular, unsymmetrical, sessile, bracteate. Calyx persistent, 

 usually gamosepaloQs with a definite number of divisions, or 

 rarely consisting of two distinct sepals. Corolla tubular, 5- 

 partite. Stamens 4, didynamous, or rarely 2 ; anthers 1- celled. 

 Ovary superior ; style 1, filiform ; ovule solitary, pendulous. 

 Fruit 2-ceUed, with 1 pendulous seed in each cell. Seeds with 

 a little fleshy albumen ; embryo with a superior radicle. In 

 Olohularia there is but one carpel. 



Distribution and Numbers. — Chiefly natives of the Cape of 

 Good Hope. The species of Globularia are, however, European 

 plants. Illustrative Genera : — Selago, Linn. ; Globularia, Linn. 

 There are about 120 species. 



Properties and Uses. — Of little importance. 



Orde r 209. Veebenace^, the Vervain Order. — C haracter. — 

 Herbs, shrubs, or trees. Leames opposite or alternate, exsti- 

 pulate. Calyx inferior, persistent, tubular. Corolla irregular, 

 usually more or less 2-lipped. Stamens 4, usually didynamous, 

 or rarely equal ; or sometimes there are but 2 stamens ; anthers 



