STANDLEY — ALLIONIACEAE OP MEXICO. 393 



we find any approach to the dichotomous method of branching. Other distinguish- 

 ing characteristics are the dense and ample inflorescence, paler lower surface of the leaf 

 blades, long racemes of flowers, and sessile leaves. 



3. Salpianthus arenarius Humb. & Bonpl. PI. Aequin. 1: 138. pi. 44- 1808. 

 Boldoa lanceolata Lag. Gen. & Sp. Nov. 10. 1816. 



Type locality, "In arenosis maritimis mare Pacifici ad Acapulcum." 



Specimens examined: 



Jalisco: Fields, Tuxpan, February, 1904, Purpus 509. 



Comma: Colima, 1891, Palmer 1204; Acapulco, 1894-5, Palmer 195; Acapulco, 



Beechey. 

 Michoacan or Guerrero: San Geronimito, April 1, 1899, Langlasse 728; Las 



Salinas, alt. 5 meters, May 9, 1898, Langlasse 153. 

 Oaxaca: Canada, oberh. Totolapam, January 3, 1896, Caec. & Ed. Seler 1703; 



Tehuantepec, 1910, Orcutt 3291. 

 Of indefinite locality: Pinotepa a lac de Tututepeque, Galeotti 586. 

 Langlasse, in connection with one of the specimens cited above, states that the com- 

 mon name of the plant is susucua and that it is used as a remedy for the sting of 

 scorpions. 



4. Salpianthus macrodontus Standley, sp. nov. 



Stems 1 to 2 meters high, Bingle or clustered, bright green, striate, much branched, 

 usually herbaceous throughout, but often persisting for more than a yeac, finely 

 puberulent throughout, rather more densely so above; leaf blades ovate or lance- 

 ovate, 5 cm. long or usually less, acute, attenuate at the base to the slender petiole, 

 bright green, puberulent on both surfaces; petioles half as long as the blades or less; 

 inflorescence cymose or rarely racemose at the ends of the branches, loose and open, 

 leafy; perianth 7 or 8 mm. long, slightly expanded above, purplish, becoming brown 

 in age, puberulent; pedicels 2 mm. long or less; teeth of the perianth triangular, 

 longer than broad, acute, whitish, thin and scarious, slightly puberulent like the rest 

 of the perianth; stamens exserted about 5 or 6 mm.; fruit compressed-spherical, 

 glabrous, black and shining. 



Type in the U. S. National Herbarium, no. 636584, collected on cliffs along the sea 

 near the signal station at Mazatlan, March 31, 1910, by Rose, Standley & Russell 

 (no. 13752). 



From the nearly related S. arenarius this species differs in having the teeth of the 

 perianth twice as long, more acute, and not villous, the stems and leaves less pubescent, 

 the leaves greener and more acute, and the petioles longer and more slender. The two 

 species seem to have quite distinct ranges, the proposed species occurring to the north 

 near the coasts of Sinaloa and Sonora, while S. arenarius occurs farther south. 



Other specimens examined: 



Sinaloa: Vicinity of Culiacan, September 22, 1904, Brandegee; Ymala, 1891, 

 Palmer 1722; moist field near Villa Union, April 2, 1910, Rose, Standley & 

 Russell 13959; sandy soil along river at Fuerte, March 27, 1910, Rose, Standley 

 & Russell 13G72; along an arroyo near San Bias, March 22, 1910, Rose, Standley 

 d- Russell 13212; dry hills, Culiacan, April 21, 1910, Rose, Standley & Russell 

 14945. 

 Sonora: Alamos, September, 1890, Palmer 310 and 720; vicinity of Alamos, 

 March 16, 1910, Rose, Standley & Russell 12905; about 5 miles below Minas 

 Nuevas, March 12, 1910, Rose, Standley & Russell 12689. 

 At San Bias, Sinaloa, the common name of the plant was given as guayavilla; this 

 is said to be applied because the odor of the plant is similar to that of the cultivated 

 "guayava." At Alamos the stems were seen used for the walls of the huts of some 

 of the natives. 



