OF ARTS AND SCIENCES. 103 



VII. 



CONTRIBUTIONS FROM THE GRAY HERBARIUM OF HARVARD 

 UNIVERSITY, NEW SERIES. 



III.* — ADDITIONS TO THE PHiENOGAMIC FLORA OF 

 MEXICO, DISCOVERED BY C. G. PRINGLE 



IN 1891-92. 



By B. L. Robinson and H. E. Seaton. 



Presented January 11, 1893. 



Thalictrum tomentellum. Polygamo-dioecious : stem striate, 

 fistulous, finely and densely pubescent : leaves tripinnate : petioles 1-2 

 inches long, tomentulose as well as the rachis and petiolules : leaflets 

 suborbicular, subcordate, finely pubescent above, paler and tomentu- 

 lose below, shallowly 3-lobed ; lobes rounded, entire or with 2-3 

 rounded teeth : inflorescence pyramidal, subnaked : sepals 4—5, ovate- 

 elliptical, 2 lines long : stamens spreading ; anthers with rather long 

 setiform tips : fruiting heads nodding on the pedicels ; carpels about 

 10, scarcely stipitate, lanate, rugose-reticulate, hispidulous, very acu- 

 minate, and tipped with a very long filiform finally deciduous style. — 

 Low lands about Lake Patzcuaro, Michoacan, July, 1892 (n. 4143). 

 Differing markedly in its fine soft pubescence from various allied 

 species. 



POLYGALA MiCHOACANA. Perennial, glabrous : stems several, 

 slender, erect, approximate, angulate, simple, or with a few long slen- 

 der erect branches : leaves small, lance-linear, scarcely spreading, 

 sessile, very sharply acuminate, 2-4 lines in length, not exceeding ^ 

 line in breadth : spikes terminal, 1-2 inches long : bracts caducous, 

 awl-shaped, very acute, purple, f line long: flowers small, short- 

 pedicelled, nodding, deflexed m fruit : sepals narrow, appearing very 

 acuminate through the infolding of the margins, greenish white with 

 purple midribs, the three smaller acute, the alie pointed but obtuse, 



* The two papers published by B. L. Robinson in these Proceedings, Vol. 

 XXVI. pp. 164-176, and Vol. XXVII. pp. 165-186, are regarded as Nos. I. 

 and II. of this series. 



