148 FLOWERS OF ROCKS, WALLS, ETC. 



downy, pinnate, leaflets elliptic, in 5-12 pairs, flower white, veins 

 crimson, with a small leaf at the base, pods jointed, curved, monililorm. 



Horseshoe Vetch (Ilippocrepis comosa, L.) 



This plant is found at the present day (not in any earlier beds) in 

 Western and Southern I-lurope and North Asia in the North Temperate 

 Zone. In Great Britain it is found in South Devon and Somerset in 

 the Peninsula province; in the whole ol the Channel province, except 

 in S. Hants; and in the Thames province, except in .Middlesex; in 

 An^lia, except in Hunts; in the Severn province, excejjt Monmouth; 

 only in Glamorgan and Carnarvon in Wales; and in the Trent pro- 

 vince; in Mid Lanes; in the H umber province, not in N.E. York; 

 elsewhere northward in Western Ireland, Ayr, and Kincardine, and it 

 ascends in Yorkshire to 1800 ft. 



The Horseshoe Vetch is especially prevalent in the chalk districts, 

 where it is a conspicuous hill-side plant, growing" on stony and rocky 

 pastures. It is accompanied by Mountain Flax, Rock Rose, Man 

 Orchis, Pyramidal Orchis, Vio/a calcarca, Polygala serpyllacca and 

 P. calcarea. Field Mouse-ear, .Snapdragon, &c. 



This plant has the Lotus habit, not growing very tall, but sub- 

 erect or prostrate, then ascending, with inversely egg-shaped, blunt 

 leaflets, 4-13, the leaves with lobes each side of a common stalk, with 

 an odd one. 



The flowers are yellow on short stalks, and the slender flower- 

 stalks exceed the leaves. The 2 upper teeth of the calyx are united 

 below, and the petals have a long claw or stalk. The pods are stalked 

 in clusters, bent in a circle, and in shape like a horseshoe (hence the 

 names, Hippon-epis and English name above), the hollow margin con- 

 tinuous, the convex margin wavy. The pod does not break up at the 

 narrow part, but across the middle of the broader part. Each segment 

 contains two seeds, but one is sterile. 



The plant is usually about 6 in. high. The flowers are in bloom 

 from April to August. Horseshoe Vetch is a perennial, deciduous, 

 herbaceous plant. 



The Horseshoe \'elch has a flower in general like that of Lotus, in so 

 far as the method of pumping out the pollen is concerned. The vexillum 

 or standard has a narrow stalk or claw, and is curved, enabling one to 

 distinguish it between the vexillum and the stamens. Ihiderneath it 

 bears a flat, irregular process which fits exactly upon the nectaries, and 

 serves to close them very effectuallv. The vexillum is employed by 



