Erysimum.] VI. CRUCIFEKJE. 35 



X. ERYSIMUM. ERYSIMUM. 



Erect annuals or perennials, pale or hoary with closely appressed 

 hairs, rarely quite glabrous ; the leaves entire, or slightly toothed. 

 Flowers yellow, or rarely yellowish-white. Pod linear, nearly quad- 

 rangular from the very prominent midrib of the valves. Stigma broadly 

 capitate, or with short, spreading lobes. Seeds ovoid or oblong, the 

 seedstalk not flattened, the radicle incumbent on the back of one of 

 the cotyledons. 



A rather numerous genus in the northern hemisphere, differing from 

 Cheiranihus in the seeds, from Sisymbrium by the midrib of the valves 

 of the pod being more prominent than in all the species of that genus 

 except S. officinale. 



Plant slightly hoary. Leaves tapering at the base . . 1. E. cheiranthoides. 



Plant glabrous and glaucous. Leaves clasping the stem, and 



rounded at the base 2. E. orientate. 



1. E. cheiranthoides, Linn. (fig. 74). Treacle Mustard.— A stiff, 

 erect annual, 1 to 2 feet high, slightly hoary with closely appressed 

 hairs. Leaves numerous, of a pale green, broadly lanceolate, entire or 

 slightly toothed, tapering into a short stalk at the base. Flowers small, 

 pale yellow. Pods numerous, on spreading pedicels, seldom an inch 

 long, the stigma slightly dilated. 



In waste and cultivated places, in northern and central Europe, Asia, 

 and northern America. Diffused over a great part of Britain, but pro- 

 bably introduced. Fl. summer and autumn. 



2. E. orientale, Br. (fig. 75). Hare's-ear. — An erect, perfectly 

 glabrous, and somewhat glaucous annual, a foot high or rather more. 

 Kadical leaves obovate and stalked, the stem-leaves oblong, 2 or 3 inches 

 long, quite entire, and embracing the stem with prominent rounded 

 auricles. Flowers pale yellow, or whitish. Pods 3 or 4 inches long, 

 slender, in a loose raceme, the midrib of the valves very prominent. 



In stony fields and waste places, in central and southern Europe, and 

 western Asia, extending northwards to the Baltic. In Britain it has 

 been gathered occasionally near the southern and eastern coasts of 

 England, but appears scarcely to be permanently established. Fl. 

 spring and summer. 



XI. BRASSICA. BEASSICA. 



Annuals or perennials, either glabrous or with stiff or rough hairs, the 

 lower leaves usually deep pinnate, or lyrate, the upper ones sometimes 

 entire, the flowers yellow. Pod linear, cylindrical or nearly so, more or 

 less beaked at the top beyond the end of the valves, the beak consisting 

 either of the conical style alone, or including a portion of the pod itself, 

 with one or more seeds in it. Seeds globular, ovoid, or somewhat 

 flattened, the cotyledons folded longitudinally over the radicle. 



A numerous genus, spread over Europe and northern and central Asia, 

 comprising the Brassica and Sinapis of Linnaeus, and divided by other 

 botanists into from three to six or even more genera, variously defined, 

 according to the peculiar views entertained by each, out all aptly united 

 into one by Boissier. It is distinguished from Sisymbrium and Barbarea 

 essentially by the folded cotyledons, and in most cases by the beak of 

 the pod. Even in the first two species, and in B. nigra, where the beak 



