CRUCIFERjE. 



29 



the other two, and more or less turgid (gibbous) at the base. 

 Petals 4j with a claw and an entire or notched or cleft limb, 



rarely wanting, on a glanduliferous 

 receptacle. Stamens 6, unequal, the 

 two lateral stamens (opposite to the 

 enlarged sepals) shorter than the 

 four interior ones. Ovary free, con- 

 sisting of two carpels, with parietal 

 placentas, two-celled, bearing se- 

 veral ovules, rarely one- celled, with 

 one ovule. Style simple, some- 

 times wanting. Stigma entire or 

 two-lobed. Fruit either elongated 

 (siliquose) or short (silicidar), open- 

 ing by two valves from the base to 

 the apex, many-seeded, sometimes 

 one-seeded and indehiscent, and 

 sometimes separating transversely 

 into one-seeded joints. Seeds sus- 

 pended without albumen (peri- 

 sperm). Embryo oleaginous, pli- 

 cate, very rarely coiled. Radicle lateral (applied to the edge of 

 the cotyledons), or dorsal (applied to the back of the cotyledons), 

 or the cotyledons are accumbent, incumbent, conduplicate, etc. 



Division I. SILIQUOSjE. — Pruit linear or lanceolate (a pod), open- 

 ing, rarely not opening, many-seeded. 



Tribe 1.^ — Cotyledons flat, radicle applied to their commissure (radicle 

 commissural). 



SYNOPSIS OF THE GENERA. 



CnEiRANTHUS. — Stem shrubby at the base. Leaves eutu-e. Sepals conni- 

 vent. Stigma two-lobed. Pod linear, sometvhat four-angled. 



Matthioia. — Stem erect. Leaves entire or sinuate. Pod cylindrical. 



Barbaeea. — Herbage glabrous. Leaves lyrate-pinnate. Flowers yeUow. 



Arabis. — Leaves toothed, rarely lyrate-pinnatLfid. Flowers white. Pods 

 linear, compressed ; valves nearly flat. 



Dentaria. — Leaves pinnate. Calyx erect; sepals not gibbous. 



Cardamine. — Leaves pinnate. Calyx not erect; sepals spreading, rarely 

 gibbous. Seeds in one row. 



Fig. III. Cardamine pratensis. 



Fig. III. — 1. Fruit (pod) of Diplotaxis temdfolia; a a, valves; 5, replum or 

 partition, with the seeds attached. 2. Fruit (pouch) of Capsella Bursa-'pastoris ; 

 a, partition ; h, liorizontal section of the pouch, with the seeds attached. 



