WEATHERBY. — MEXICAN PHANEROGAMS. 425 



the perianth inconspicuous, equalling or shorter than the involucre ; 

 fruit lance-ovate in outline, acute at the apex, narrowed at the base, 

 with five narrow but prominent smooth ribs, the space between more or 

 less strongly tuberculate, glabrous or minutely strigillose between the 

 ribs.— Am. Nat. vii. 302 (1873). — Kanab, South Utah, Mrs. A. P. 

 Thompson. Chihuahua: sand hills near Paso del Norte, Sept. 20, 

 1886, Pringle, no. 1126. A specimen from Kansas, sand hills, Kearny 

 Co., Aug. 29, 1897, A. S. Hitchcock, no. 421b perhaps belongs here 

 also. 



There is in the Gray Herbarium a plant clearly referable to this 

 species, but differing from the typical form in its pubescent pedicels 

 and involucres. It seems worthy of recognition as : var. recedeno, 

 n. var., a forma typica differt pedicellis involucrisque pubescentibus. — 

 Chihuahua : between Casas Grandes and Sabinal, altitude 1550- 

 1700 m., Sept. 4-5, 1899, Nelson, no. 6351. 



In the course of a recent attempt to rearrange, with the aid of 

 Mr. Standley's excellent monograph, the Mexican specimens of 

 Nyctaginaceae in the Gray Herbarium, it became apparent that, under 

 the Vienna Rules, several new combinations in the genus' Oxybaphus 

 were required. They are accordingly proposed here, as follows : 



Oxybaphus texensis (Coult.), n. comb. Allionia corymbosa, var. 

 texensis Coult. Contr. U. S. Nat. Herb. ii. 351 (1894). Allionia texensis 

 Small, Fl. Southeast. U. S. 406 (1903). — Coulter's no. 912, from 

 Mexico, but without more definite locality, should apparently be 

 referred here. 



Oxybaphus coahuilensis (Standley), n. comb. Allionia coahuilen- 

 sis Standley, Contr. U. S. Nat. Herb. xii. 347 (1909). 



Oxybaphus melanotrichus (Standley), n. comb. Allionia melano- 

 tricha Standley, 1. c. 351. The following, not cited by Mr. Standley, 

 belongs here : Chihuahua : mountains near Pilares, 23 Sept., 1891, 

 C V. Hartman, no. 743. 



Oxybaphus pseudaggregatus (Heimerl), n. comb. Mirabilis 

 pseudaggregata Heimerl, Ann. Cons, et Jard. Genev. v. 183 (1901). 

 Allionia pseudaggregata Standley, 1. c. 356. — The following specimens 

 belong here : San Luis Potosi : alt. 1850-2500 m., 1878, Parry & 

 Palmer, no. 768 ; in montibus San Miguelito, 1876, Schaffner, no. 177. 

 Valine de Mexico, Guadelupe, ler Aout, 1865, Bourgeau, no. 651. 



Urvillea biternata, n. sp., fruticosa 1-2 m. alta glabra vel ramulis 

 minute pulverulentibus, ramis 3-5-costatis costis obtusis interdum 

 rubris inter costas planiusculis vel leviter sulcatis, foliis biternatis, 

 foliolis membranaceis glabris vel subtus praeter nervos sparse pubes- 

 centibus punctis lineisque pellucidis minute punctatis ovatis subtus 



