398 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



branches were found everywhere in the greatest abundance, often reaching a length 

 of two meters and subdividing profusely. By digging down in the sand to a depth 

 of G inches or more large numbers of the fruits were found. These are about 12 mm. 

 long, brown, and smooth. The seed is oblong, about 7 mm. long, surrounded by a 

 thick, spongy pericarp. The fruits and seeds shown in the plate (facing p. 388) were 

 photographed from specimens obtained at Mazatlan. 



Seeds were brought to Washington and planted with successful results. The plants 

 bloomed in about four weeks from the time of sowing. The young plants show a 

 cruciform method of branching; their stems and leaves are very viscid. The pedun- 

 cles at first are short but elongate rapidly, turn downward, and penetrate the sand 

 to a depth of several inches. The flowers are rather handsome, their size sufficient 

 to make them conspicuous, but the plants are not adapted to use as ornamentals 

 because they soon lose their leaves and become mats of coarse, awkward stems. 



Besides the specimens c ted from Mexico I have seen a collection from the coast 

 of southern Florida, a notable extension of range. The species should be found on 

 some of the islands of the West Indies, but so far it has not been reported. 



3. Okenia rosei Standley, sp. no v. 



Annual with prostrate, spreading stems; these slender, densely viscid and villous; 

 leaf blades ovate to oblong, entire, truncate or rounded and equal at the base, rounded 

 at the apex, of about the same color on both surfaces, pubescent to puberulent above 

 and below; opposite leaves very unequal, the larger 20 to 32 mm. long and 13 to 22 

 mm. wide, the smaller ones about 10 mm. long and 8 mm. wide; petioles of larger 

 blades 8 to 15 mm. long; peduncles at anthesis about 15 mm. long, but soon lengthen- 

 ing to 10 to 15 cm.; bracts lanceolate, 3 mm. long, with subulate tips, villous; perianth 

 about 25 mm. long, very slender at the base for about 9 mm., then becoming much 

 thicker and soon expanding into a limb 18 mm. in diameter, this 5-lobed, the lobes 

 broadly oblong, shallowly retuse; perianth villous without; stamens about 9, unequal. 



Type in the U. S. National Herbarium, no. 301784, collected by J. N. Rose at 

 Bolanos, in the State of Jalisco, September 10 to 19, 1897 (no. 2845). The plant is 

 closely related to 0. hypoguea, but that is maritime, while this grows far inland. The 

 leaves are entire instead of strongly undulate and are not extremely unequal at the 

 base as in that species; the lobes of the perianth are only shallowly retuse instead of 

 deeply cleft. 



11. SELINOCARPUS A.Gray. 



Selinocarpus A. Gray, Amer. Journ. Sci. II. 15: 202. 1853. 

 Type species, Selinocarpus diffusus A. Gray. 



KEY TO THE SPECIES. 



Leaves broadly ovate. (Perianth less than 10 mm. long) 1. 8. chenopodioides. 



Leaves linear or nearly so. 



Perianth 10 mm. long or less, with scarcely any tube 2. S. anyustifollus. 



Perianth about 15 mm. long, with a conspicuous tube 3. S. palmeri. 



1. Selinocarpus chenopodioides A. Gray, Amer. Journ. Sci. II. 15: 262. 1853. 

 Type locality, "Valleys from Providence Creek to the Rio Grande," Texas. Type 



collected by Charles Wright (no. 1707). 

 Specimens examined: 



Chihuahua: Dry calcareous bluffs, Ciudad Juarez, alt. 1,130 meters, September 



26, 1902, Pringle 11143; plains near Chihuahua, August 18, 1885, Pringle 052; 



Santa Eulalia plains, August 18, 1885, Wilkinson. 



2. Selinocarpus angustifolius Torr. Bot. Mex. Bound. 170. 1858. 

 Type locality, "Gravelly table land near Presidio del Norte," Texas. 



