Orobus
(the old Greek name used by Theophrastus; it has nothing to do with the present genus). Bitter Vetch. ORD. Leguminosae. An extensive genus of usually hardy, herbaceous perennials, mostly natives of the Northern hemisphere, and now included (by Bentham and Hooker) as a section of Lathyrus, from which it differs in having no tendril at the tip of the petiole. For horticultural purposes, however, the two genera are here kept distinct. Many species are very handsome; they thrive in almost any soil, and are readily increased by dividing the tufted rootstocks in spring. Some force readily, and make charming pot plants for cool-house decoration. The species here described are those generally found in gardens.
O. atropurpureus (dark-purple). A synonym of Vicia sicula. O. aurantius (orange-coloured).* fl. deep yellow; peduncles elongated, shorter than the leaves. June. l. with five or six pairs of lanceolate, bluntish leaflets. Stems simple, angular. h. 1 1/2ft. Caucasus, 1818. (S. B. F. G. ser. ii. 198.) O. canescens (canescent). A synonym of O. filiformis. O. filiformis (thread-formed). fl. white, with a tinge of blue; peduncles many-flowered, longer than the leaves. May. l. with usually two or three pairs of linear, bluntish, pubescent or dotted leaflets. Stem tetragonal. h. 1 1/2ft. South Europe, 1816. SYN. O. canescens. (B. M. 3117.) O. Fischeri (Fischer's). A synonym of Vicia sicula.
O. flaccidus (flaccid).* fl. purple; vexillum with two prominent obtuse teeth near the middle, which embrace the inner petals; peduncles terminal or axillary. May. l. remote, spreading, of two or three pairs of opposite, very long, linear, attenuated, glabrous leaflets, dark green above, paler beneath; stipules large, semi-sagittate. Stem erect. h. 6ft. Croatia, &c. (B. M. 2937, under name of O. stipulaceus, and wrongly ascribed to North America.) O. hirsutus (hairy). fl. red; racemes axillary, twice as long as the leaves, few-flowered. May. l. ovate, acute, with parallel nerves. h. 1ft. Thrace, &c., 1822. (B. M. 2345; S. B. F. G. ser. ii. 302.) O. luteus (yellow). fl. yellow; peduncles elongated, many-flowered, about equal in length to the leaves. June. l. with three to five pairs of elliptic-lanceolate, mucronulate leaflets, which are glaucous beneath. Stems simple, angular. h. 1ft. to 2ft. Europe, 1759. (L. B. C. 783; S. B. F. G. ser. ii. 115.) O. niger (black). fl. purple; peduncles many-flowered, longer than the leaves. June. l., leaflets elliptic, mucronulate, with almost parallel nerves. h. 3ft. Europe (Britain). (B. M. 2261; Sy. En. B. 407.) O. pannonicus (Hungarian).* fl. very variable in colour, ranging from white and cream tinged with rose, to purple and white and yellow; peduncles many-flowered, longer than the leaves. May. l. with two or three pairs of linear, mucronate leaflets. Stem simple. h. 1ft. South Europe, 1794. (J. F. A. 39; S. B. F. G. 22.) O. p. varius (various-flowered). fl. with the standard rose-coloured, and the keel and wings yellowish; peduncles many-flowered, longer than the leaves. May. l. with three or four pairs of linear-lanceolate, mucronulate leaflets. Stems simple, angular. h. 1 1/2ft. Italy, 1759. (B. M. 675.) O. sessilifolius (stalkless-leaved). fl. purple, in few-flowered racemes. May. l., leaflets narrow, dark green, almost sessile. h. 1ft. Greece, &c., 1823. (B. M. 2796; S. F. G. 692.) O. variegatus (variegated). fl. finely variegated, small. Early summer. l. with two or three pairs of lanceolate leaflets. Stems simple, flexuous. h. 1ft. Europe, 1821. (S. B. F. G. ser. ii. 28.) O. vernus (spring).* fl. purple and blue, with red veins, the keel tinted with green, the whole changing to blue, secund, nodding; peduncles axillary, many-flowered, shorter than the leaves. Spring. l. with two or three pairs of ovate-lanceolate, acuminate, shining leaflets. Stems simple, flexuous. h. 1ft. Europe, 1629. (B. M. 521; S. F. G. 691.)