Plants Collected in Paraguay. 95 



Piptadeilia rigida, Benth., Hook. Jour. Bot., iv, 338. 



Asuncion (744 and 825). Flower November; fruit May. 



A tree similar to the two preceding species, with very smooth, 

 light-gray bark, growing from 10 to 16 m. in height, common in 

 the vicinity of Asuncion. Petiolar gland green, elongated, cup- 

 shaped. Flowers greenish-yellow, in axillary, cylindrical spikes 4 

 or 5 cm. in length. Pinnae 2-6 pairs, ultimate segments somewhat 

 falcate, dark green, 16-30 pairs. Legume 3-10 cm. long and 1-1 J 

 cm. broad, containing 2-6 flat, round seeds, which are attached by 

 long threads to the upper suture, and enveloped in a hyaline mem- 

 brane. 



Prosopis Algarolbilla, Gris., PI. Lorentz, 83. 



Near Luque (851). December. 



An ungainly, very thorny tree, with straggling branches, 5-1 m. 

 high, growing on the open campo near the railroad track between 

 Paragua and Luque. This is known to the natives as Espanilla, a 

 name commonly given to spiny leguminous trees. Also often called 

 Algarobo. Flowers white, in slender spikes 6-10 cm. long, either 

 among the leaves or on naked branches. Legumes slightly curved, 

 constricted between the seeds, 7 or 8 cm. long, containing 6-8 seeds. 

 Leaves 2-5 cm. long, glabrous or the rachis puberulent; leaflets 

 10-25 pairs, oblong, 3-nerved, the lateral nerves on the margins, 

 mucronulate, .3-5 mm. long, sessile. Branches very flexuous. 



Prosopis cainpestrJS, Gris., PI. Lorentz, 84. 



Between Villa Rica and Escoba (481). 



This tree, so far as my specimens go, differs from the preceding 

 species only in having fewer and smaller leaves (2-3 cm. long), 

 smaller leaflets (2-3 mm. long), and longer and much-curled legumes. 

 Also called Espinilla. 



Prosopis ruscifolia, Gris., PL Lorentz, 82. 



Pilcomayo River (1098). 



An algarobo 8-10 m. in height, very smooth; bark dark gray. 

 Leaves pinnate, with 3 or 4 pairs of large, smooth, elliptical leaflets. 

 Without flowers or fruit. The thorns of this tree are gigantic, 

 some of them nearly a foot long and half an inch thick at the base, 

 their wood densely hard, sharp-pointed, looking more like spears 

 than thorns. 



