168 BRITISH BOTANY. 



Roots slender, creeping, furnished with rounded tubercles 

 (knobs). Stems narrowly winged, ascending. Leaves with 2-4 

 pairs of elliptical leaflets, which end in setaceous points ; sti- 

 pules half arrow-shaped, entire or toothed. Flowers 2-4, on a 

 peduncle which usually surpasses the leaves. Calyx-teeth very 

 unequal, the upper short, convergent. Legume nearly cylindri- 

 cal, tapering at the base, black when mature. Seeds round, 

 smooth, hilum occupying about one-third of the circumference of 

 the seed. 



On heaths and in woods. Perennial ; May- August. 



Var. /S. Orobus tenuifolius, Roth. — Leaflets narrow, linear- 

 lanceolate. Not rare in North Wales. 



£i. niger, Wimm. — Orobus niger, Lin. and Sm. Black Bitter 

 Vetch.— T^.B.s. 2788. l.b.s. 313. 



A. 1. C. 2. Lat. 56-57°. Alt. 0-300 yds. Tem. 45°-? 



Stems angular, not winged, erect, much branched. Leaflets 

 with Z-Q pairs, oblong-elliptical (ovate-oblong), obtuse and api- 

 culate (with a small mucro), the common petiole (rach) ending 

 in a subulate point (not with a tendril) . Flowers 4-8, on com- 

 mon peduncles, which surpass the leaves. Calyx-teeth unequal, 

 the upper short, triangular convergent. Legume linear, slightly 

 compressed, tapering at the base, finely veined. Seeds ovate, 

 with a linear hilum, which is equal to one-third of the circum- 

 ference of the seed. The whole herbage turns black in drying. 

 — This character is not peculiar to L. niger ; L. macrorhizus 

 sometimes assumes this colour in the herbarium. 



Mountainous passes in Scotland ; rare. Per. ; June, July. 



Ii. maritimus, Fr. — Pisum maritimum, L. and Sm. Seaside 

 Pea.— E.B. 1046. l.b.s. 311. 



A. 5. C. 5. Lat. 50-61°. Alt. 0. Tem. 51-47°. 



Stem angular, not winged, reclining at the base, erect upwards, 

 flexuous. Leaves on a non-winged petiole, terminating in a sim- 

 ple or branched tendril ; leaflets elliptical or oblong, in 4-6 pairs ; 

 stipules leaf-like, ovate, cordate at the base. Flowers numerous, 

 on erect and stout peduncles, which are not muCh more than half 

 as long as the leaves. Calyx-teeth unequal, the upper short, tri- 

 angular, and converging. Legume compressed, cuneate at the 

 base, terminated by the long, flattened style. Seeds numerous, 

 black, smooth; hilum one-third of the circumference of the seed. 



On pebbly sea-beaches ; rare. Perennial ; July, August. 



