153 Preussii. 



PREUSSII. 9. 



Pods thin-coriaceous to cartilaginous, fleshy except in 

 some Preussii forms, iutlated, 2-5 ciu. long, 1-2 cm. high or 

 or wide, apiculate or shortly beaked, elliptical to round or 

 oblate in cross section, both sutures inclined to be produced 

 within but never 2-celled, in Preussii dorsal suture a mere line 

 ■within, pod mostly stipitate, never deeply sulcate, erect or 

 ascending, rarely reflexed in sabulosus, on very stout pedicels, 

 smooth or very minutely and sparsely puberulent when young, 

 obscurely cross-lined, or faintly reticulated, opening nearly 

 to the middle from the tip along both sutures. Flowers large, 

 2-3 cm. long, widely spreading to reflexed. Petals rather long 

 and long-clawed. Banner arched 45 to 90 degrees near the 

 tip of keel or beyond calj^x teeth, oblong-ovate, about 1-1.5 

 cm. long, with sides much reflexed. Wings narrow, 2-4 mm. 

 longer than keel, obtuse, somewhat arched. Keel base straight, 

 tip mostly gently arched to erect or a little more, rounded, near- 

 ly always purple, 3-4 mm. high. Calyx laterally flattened, 

 5-10 mm. long, about 3 mm. high, cylindrical or not cara- 

 panulate, teeth mostly short and broad. Bracts hyaline, tri- 

 angular, not longer than the pedicel which is 2-4 mm. long. 

 Peduncles rigid, stout, erect, tapering, coarsely grooved, 

 mostly as long as leaves. Upper leaves 1-2 dm. long except in 

 asclepiadoides, short-petioled, with rigid and tapering ra- 

 chis, spreading. Leaflets thick and leathery, flat, smooth or 

 never more than puberulent, large, distant, gradually smaller 

 above on rachis. Stipules small for the plant, deltoid, green, 

 reflexed, about 4 mm. (rarel}^ 8 mm.) long. Stems except 

 in forms of Preussii thick and stout, 1-3 ft. high. Mostly 

 coarse and tufted perennials little branched, growing in salty 

 or alkaline or very poor clay soil on flats or the equivalent. 

 Pubescence of minute, wide, flat hairs closel}^ appressed and 

 narrowed below and tapering above and attached at or very 

 near the end, mostly absent altogether. This group shows 

 the same remarkable variation in the pods as in A. gracil- 

 entus, and like it is inclined to have the ventral suture pro- 

 dwed a little within, but it lacks the soft and flabby leaves 

 and minutely woolly pubesceTice and peculiar roughness of 

 leaf surface, and the whole plant has a peculiar leathery 

 suceulencf;, and rigidity, and never grows in sweet soil. 

 Pla:;ts blooming in summer. Lower Temperate life zone, 

 rarely in the edge of the Tropical. 



