1913] Woodward,— Variation in Arenaria lateriflora 209 
Rupr. Mém. Acad. Pétersb. sér. 7, xiv. n. 4, 51 (1869). Leptilon 
canadense (L.) Britton in Britton & Brown, Ill. Fl. iii. 391 (1898). 
L. canadense pusillum Daniels, Fl. Boulder, Col. 239 (1911), as to 
plant but excl. name-bringing synonym.— Common and widely dis- 
tributed through temperate North America, Mexico, and in scattered 
localities south even to Chili; also an introduced weed in waste places, 
etc., in the Old World. 
Var. GLABRATUS Gray. Tall and (for the species) robust, with 
smoothish stem, the trichomes few, scattered, and very short, ascend- 
ing or subappressed: branches of the large inflorescence long (1--1.5 
dm.) simple, apt to be closely flowered and appearing inversely 
racemose or even almost spicate.— Pl. Lindh. ii. 220 (1850).— 'TExas: 
between the Colorado and Nueces Rivers, Berlandier, no. 2555; fields 
in sandy loamy soil near Bracken, Bexar Co., Groth, no. 83; prairie 
north of the Llano among granite rocks, Lindheimer, no. 626 (444). 
New Mexico: Forest Nursery, Fort Bayard, Watershed, Grant Co., 
Blumer, no. 33; cañons, Tierra Blanca, Sierra Co., Metcalfe, no. 1229. 
CHIHUAHUA: near Lake Santa Maria, E. W. Nelson, no. 6388. CALI- 
FORNIA: Wilson’s Lake, Nevin, no. 8. 
Gray HERBARIUM. 
ON VARIATION IN ARENARIA LATERIFLORA. 
R. W. Woopwarp. 
WHILE collecting on the low grounds near the beach at Westerly, 
Rhode Island, June 5, 1913, I was struck by the display of Arenaria 
lateriflora, the season’s vegetation not being far enough advanced to 
overtop the Arenaria, which was abundant, and conspicuous with its 
white flowers, over considerable areas. Equally abundant, but grow- 
ing by itself and not mingling with the other, was a plant with smaller 
white flowers, which I at first took to be a different species, but which 
proved on examination to be a form of Arenaria lateriflora, or at least 
closely related to it. Many specimens of these plants were examined, 
both in the field and later, and the differences between them are so 
marked and so constant that it seems worth while to place them upon 
record. 
The petals of the first plant average 7.5 mm. in length, and the 
prominent stamens are about twice the length of the calyx, equalling 
