MEXICAN AND CENTRAL AMERICAN UMBELLIFER^ 1 53 



Prionosciadium sp. ? 



A somewhat similar species, with very large basal leaves ternate 

 then pinnate, the rachis strongly winged and toothed, the leaflets lan- 

 ceolate and acuminate but pubescent on the lower surface and not at 

 all glaucous. 



Sinaloa : above Colomas, Rose 1815, July 14, 1897. 



These specimens have only leaves, and the generic position is there- 

 fore doubtful, but in habit and foliage they are very similar to the 

 species of Prionosciadium. 



33. RHODOSCIADIUM Watson, Proc. Am. Acad. 25 : 151. 1890. 

 A genus of three species endemic in Mexico. In addition to the 

 type species, cited below, two others have been described — R. dis- 

 sectum C. & R. and R. glauaim C. & R. 



Rhodosciadium pringlei Watson, Proc. Am. Acad. 25 : 151. 1890. 

 Jalisco: Rose 2567, August 25, 1897; near Bolanos, Rose 2865, 

 September 8, 1897 ; on barranca near Guadalajara (type locality), 

 Rose & Hough 4830, July 9, 1899. 

 In the collections of 1897, cited above, the specimens differ from 

 the type in having very conspicuous calyx-teeth. 



Rhodosciadium dissectum C. & R. Contr. Nat. Herb, 3: 309. 1895. 

 Oaxaca : Las Sedas (type locality). Rose & Hough 4630, June 16- 

 21, 1899. 



34. DEANEA C. & R. Bot. Gaz. 20: 372. 1875. 



An endemic Mexican genus, founded upon two species. The dis- 

 covery of five additional species gives an opportunity of stating again 

 its relations with allied genera, and is also the occasion for enlarging 

 somewhat the generic boundary. The only boundary that seems to 

 need explicit definition at present is that whicli separates Deanea from 

 Prionosciadium. So far as known, these two genera are constantly 

 distinct in their stylopodia, that of Deanea being conical, that of 

 Prionosciadiutn depressed. The relative size of the fruit in the two 

 genera, which at first was supposed to be a usable character, is 

 found to be of no avail, as the new species described in this paper ex- 

 hibit large fruit in Deanea and small fruit in Prionosciadium. Also 

 the fruit of Deanea is found to be not always round or oval, but in 

 some species it is broadly oblong. 



When the species of the two genera are contrasted in appearance 

 the difference is greater than can be expressed easily. The species of 



