ROBINSON, — SPECIES OF MIMOSA. 311 



Tonduz, no. 1568; Honduras, J. D. Smithy no. 5215, Nlederlein. lu 

 a considerable series of specimens it lias been impossible to find any 

 constant or satisfactory characters or combinations of characters to sepa- 

 rate this species from the following forms here included as varieties. 

 The differences of pubescence, which are striking in extremes, undergo 

 the most gradual aud complete intergradation and appear to be corre- 

 lated with no other important distinctions. It is probable that all the 

 forms here given cross freely when occurring in the same region. 



Var. strigosa (^M. strigosa, Willd. 1. c). Leaflets acutish, beset 

 upon both surfaces with coarser strigose hairs. — Costa Rica, Oersted, 

 no. 8. 



Var. floribnnda {M. floribunda, Willd. 1. c 1031). Leaflets acut- 

 ish, glabrous above, covered below with appressed sette : pedunculate 

 heads mostly collected in almost naked terminal racemes: corolla puber- 

 ulent to tomentulose. — Jalisco, Po/wer, no. 705 (coll. of 188G); Ori- 

 zaba, Botteri, no. 569, Seaton, no. 141 ; Vera Cruz, Bourgeau, no. 

 1541, C. L. Smith, nos. 1142, 1716, 1719, Nelson, nos. 72, 160; 

 Puebla, Nelson ; Guatemala, Hayes, J. D. Smith, no. 3308. Captain 

 Smith's no. 5764 from Costa Rica, and Kerber's nos. 119 and 353 from 

 S. Mexico are good examples of transitions between M.alhida and its var. 

 ■floribunda. It is probable also that leaflets which are at first pubescent 

 above are sometimes glabrate in age. 



Var. enryphylla. Scarcely armed : leaflets broad, obovate, rounded 

 and merely mucronulate at the apex, glabrous and somewhat lucid 

 above, appressed-villous beneath : corolla glabrous. — Collected by 

 E. W. Nelson in the valley of Jiquipilas, Chiapas, altitude 675 to 850 

 m., 16 to 18 August, 1895, no. 2927 (in herb. U. S. Nat. Mus.). 



Var. glabrior. Stem and branches nearly glabrous : leaflets acute 



or acutish, glabrous above, sparingly setose beneath : corolla glabrous. — 



M. Velloziana, Micheli in J. D. Smith, PI. Guatem. &c. iv. 49, not Mart. 



— Coll. Heyde & Lux at Malpais, Dept. Santa Rosa, Guatemala, altitude 



1230 m., no. 4133 of J. D. Smith's distrib. 



* * Pinnae 1 to several pairs ; leaflets 3 to several pairs, smaller. 



■t- Stems herbaceous (sometimes becoming sligiitly ligneous in M. pitdica), hirsute 

 with spreading often tawny liairs ; pinna 1 or 2 (closely approximated) pairs. 



++ Leaflets ovate or obovate : fruit finely pubescent upon the valves. 



8. M. Skinneri, Benth. Low, much branched hirsute annual : 



leaves with 2 or 4 digitately arranged secondary rhachises ; leaflets 



obovate, 3 to 8 pairs, crowded, obtuse, very sensitive, glabrous above, 



appressed tawcy-villous below,; infra-stipular spines stramineous, straight : 



