186 



3 Co UK DE St. PlERHE, 



Genera, March 12, lS9f). 

 Dear Sir: Having examined the five specimens of Thalictrum recently sent by 

 you, I arrive at the following conclusions: 



1. Pringle's No. 7448 is to he referred to the peltatum DC. Its leaflets :ire of the 

 same shape and nearly of the same size with those of that species and glabrous as they 

 are, as you may see in the subjoined tracing of one of the leaves of the Prodromus 

 type. True it is that one of the fruits accompanying that in 7848 bears a rather long 

 style; but I must point out to you the fact that, as shown in my tracing, the fruit 

 of the peltatum "when young has also a very long style, which afterwards gets broken, 

 so that only part of it remains at the top of the fruit when ripe. 



2. T. jaliscanum ( Hose No. U810) and the Pringlei (Pringle No. 2478) have both touch 

 smaller leaflets than the peltatum DC; but this may be due to their having been 

 gathered higher on the plants on superior and smaller leaves, as these lcallets also 

 are quite glabrous ; and finally as the frnits of both specimens agree with those of the 

 peltatum, I suggest that those species are perhaps mere varieties of the latter. 



3. Your T. cuernavacanum (Pringle's No. 7238) really seems to me to be a distinct 

 specios, on account of its smaller and pubescent leaflets, although its fruits much 

 resemble that of T. peltatum. 



4. The Guatemala specimen, labeled T. peltatum (Ileyde No. 164), also looks as a 

 distinct species, on account of its strigulose fruits and leaflets. 



Availing myself of your kind permission to do so, I shall retain those five speci- 

 mens, much regretting on my side not to be able to supply you with any fragment 

 of the already too meager Prodromns type. 



These Thaliotrnms have a very great interest forme, being to my knowledge (with 

 T. iehangense Lee.) the only plants having composite leaves with peltate leaflets. I 

 have already drawn attention to this irregularity in the last sitting of the ISritish 

 Association at Bristol. 



I remain, yours, very truly, 



(Signed) C. De Candolle, 



KEY TO THE MEXICAN ANI> CENTRAL AMERICAN SPECIES OF THALICTRUM. 



a. Leaflets peltate or subpeltate. 



b. Akenes at least twice as lony as broad. 



c. Glaucous throughout; ahencs tapering at base or with a short but eridetit stipe, narrowly 



elliptical. 



d. Leaflets large, with very broad, shallow erenations. 



Thalictrum peltatum DC. Prodr. 1:11. 1824. Plate XXI. 



Apparently a tall, coarse plant, glabrous and very glaucous throughout; upper 

 leaves twice tern ate; leaflets very large (the upper ones 8 cm. in diameter), peltalo, 

 orbicular, with a few large erenations or lobes above, nearly entire below, rather 

 strongly veined, pale on both sides; inllorcsceuce an open panicle, 2 dm. Jong (in 

 the only specimen seen;; fruit somewhat oblong, 5 to G mm. long, tapering at base 

 (almost stipitate); one edge nearly straight, the other rounded; the sides with 2 or 3 

 nearly parallel nerves either distinct or united by cross nerves; style very long (12 

 mm. or more) and somewhat persistent, 



Collected by C. G. Pringle on bluff of barranca above Cuernavaca, Morelos, August 

 23, 1897 (No. 7418), and distributed as T. pringlei. It differs from T. pringlei in its 

 fruit and foliage. 



I have described this specios from Mr. Pringle's specimens, since De Candolle's 

 description really applies equally as well to any one of the peltate-leaved species. 



