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A NEW SPECIES OF DICHONDRA 

 By Homer D. House 



By most authors the Dichondraceae Dumort, is regarded as 

 a tribe or subfamily of the Convolvulaceae. It seems, however, 

 that the character of two separate carpels with basally attached 

 styles is of sufficient morphological importance to warrant the 

 separation proposed by Dumort. 



The following new species from southern California and the 

 adjacent islands is related to D. 7'epens^ and that relationship 

 together with the position of the other species native to the 

 United States is best expressed by the following key: 



Sepals obtuse 



Sepals shorter than the capsules, about 1.5 mm. long; corolla 

 exceeding the calj'x 

 Leaves broadly reniform, entire, 2 to 5 cm. broad, nearly 



glabrous. Southern California and adjacent island.s D. occidentalis 



Leaves cordate-orbicular, repand-crenate, i to 2 cm. broad, 

 pubescent. West Indian. D. repens 



Sepals longer than the capsules, 1.5 to 3 mm. long; corolla 

 shorter than the calyx; plant pubescent or glabrate; 

 sepals conspicuously spatulate. Southeastern U. S. D. Carolinensis 



Sepals acute; leaf blades silver}--pubescent; corolla exceeding 



the calyx. New Mexico, Arizona and Mexico. D. argentea 



Dlchondra occidentalis sp. nov. 



Stem perennial, slender, creeping, branching, 10 to 40 cm. 

 long, glabrate, or appressed pubescent when young witli silvery 

 hairs: leaf-blades large, broadly reniform, 2 to 5 cm. broad, i to 

 3 cm. long, usually retuse at the apex, glabrous or with some 

 scattered pubescence, dark green above, paler beneath, shallowly 

 cordate and somewhat cuneate at the base, 7-nerved; petioles 5 

 to 8 cm. long, pubescent toward the base: peduncles filiform, i 

 to 2 cm, long: calyx turbinate, densely pubescent, its lobes obo- 

 vate, 1.5 mm. long, blunt or rounded, scarcely enlarged in fruit: 

 corolla nearly twice as long as the calyx, subrotate, white, its 



