185 



Waltheria rhombifolia Donnell Smith, I Sot. Gaz. 23 : 3. 1897. 



This epeciea, based on a common plant of Costa Rica, seems not to be specifically 

 different from the above. 



cc. Filament* not united to the top. 



Waltheria glomerata Presl, Reliq. Haenk. 2 : 152. 1886. 



Shrub 15 to 21 dm. high; calyx <> nun, long; sepals broad, 1 mm. long; petals 

 exserted; stamens united only at base. 



NOTES ON SOME MEXICAN SPECIES OF THALICTRUM. 



While attempting to revise the Mexican and Central American spe- 

 cies of Thalictrum I found that there were five very distinct species 

 with peltate leaflets. Only two species with sueh leaflets had hereto- 

 fore been described from this region. One of these is the very recent 

 T.pringlei, of which we have a duplicate type in the National Herba- 

 rium. The other is the T. peltatum DC, which was very briefly 

 described in the Prodromus and said to have come from Mexico. 



Lecoyer, in his monograph of this genus, cited as belonging to this 

 species specimens from two very widely separated localities, namely, 

 Costa Rica and Agua Calientes. From my knowledge of the flora of 

 these two regions I doubted these references, and the specimens seemed 

 to confirm my suspicions. 1 could not, however, without knowledge of 

 the type locality and with the very meager characterization in the 

 Prodromus describe definitely what was really T. peltatum. This led 

 me to send specimens and a brief note to M. Casimir de Candolle, at 

 Geneva, in whose herbarium is deposited the type of T. peltatum. M. 

 de Candolle replied at some length and inclosed a tracing of the foliage 

 and akenes. His letter is so clear and exhaustive that it seems advis- 

 able to publish the correspondence in full, as it can not fail to be of 

 interest and of value when a more exhaustive study of this genus is 

 made. 



February 27, 1899. 

 M. Casimir i>k Caxdoi.lk, 



Cour de St. Pierre 3, Genera, Switzerland. 



My Dear Sik: I am about to trouble you once more, aud this time with a Thalic- 

 trum. Thalictrum peltatum was described in the Prodromus, volume 1, page 11, but 

 with no more definite locality than " Mexico," Lecoyer cites two localities for this 

 species — Costa Rica and Agua Caliente. We have a specimen in the National Her- 

 barium, from Guatemala, which seems to answer his description, but I am not wure 

 that this is the same plant as described in the Prodromus. I have five specimens 

 with peltate leaflets, and at least three of them are undescribed. It is very impor- 

 tant to make out definitely what is the true T. peltatum. I inclose leallets and fruit 

 of all these five species, and if you can refer any one of these definitely to T. pelta- 

 tum it will bo a great help to me. I should like, indeed, to have a fragment from 

 your specimen, but since I know how precious these plants are, I do not feel as 

 though I ought to ask for it. 



Yours, very truly, 



J. N.Rosk. 



22114 4 



