260 Rhodora [DECEMBER 
Consequently it has seemed worth while to systematize the American 
treatment of this species and to make the necessary new combinations 
under Arenaria, in which genus the species seems properly placed. 
The differences between the varieties are stated in the following key: 
A. Leaves elliptical or ovate-lanceolate. 
B. Leaves puberulent on the margins and on the midribs beneath, or 
occasionally puberulent throughout. 
1. A. lateriflora L., var. typica (Regel) St. John. 
B’. Leaves glabrescent or glabrous. 
2. A. lateriflora L., var. glabrescens (Regel) Robinson. 
A’. Leaves linear, linear-elliptic, or linear-lanceolate. 
C. Leaves puberulent on the margins and the midribs beneath, occa- 
sionally puberulent throughout. 
3. A. lateriflora L., var. angustifolia (Regel) St. John. 
C’. Leaves glabrous........ 4. A. lateriflora L., var. Taylorae St. John. 
It will be seen that Regel’s 8. intermedia has not been taken up. 
It has not seemed advisable to try to separate the broad, pubescent- 
leaved plants into those with “elliptical obtuse or rarely acute leaves” 
(Regel’s a. typica sensu stricto) as opposed to those with “ oblong- 
elliptic or oblong-lanceolate obtuse or rarely acute leaves” (Regel’s 6. 
intermedia). If such a distinction can be drawn, it does not seem to 
be of any taxonomic or phytogeographic importance. 
1. ARENARIA LATERIFLORA L., var. typica (Regel) n. comb. 
Mohringia lateriflora (L.) Fenzl, var. typica Regel, Fl. Ostsibirien i., 
Bull. Soc. Nat. Mose. xxxv. 377 (1862).— Perennial with slender 
terete minutely retrorsely pubescent stems which are simple or freely 
branching especially at the base, 0.5-4 dm. high: leaves bright green, 
opposite, entire, sessile, slightly connate, elliptical or ovate lanceolate, 
puberulent on the margins and on the midribs beneath, occasionally 
throughout, 5-30 mm. long, 3-14 mm. wide: inflorescence lateral or 
becoming so, cymes one or more borne from the upper axils, 1—6- 
flowered; pedicels subtended by minute paired bracts, one or more of 
the uppermost pedicels bibracteolate near the middle; sepals green, 
hyaline-margined, ovate, obtuse, glabrous, 2-3 mm. long; petals 
usually exceeding the sepals 2-3 times.'— Abundant on gravelly and 
turfy shores, in thickets and borders of woods, and meadows, Arctic 
America south to Pennsylvania, Ohio, Ill., S. Dakota, Missouri, and 
the mountains of Montana, Idaho, Colorado, Utah, New Mexico, 
Washington, and Oregon; also in boreal Eurasia. A few typical 
specimens in the Gray Herbarium and the Herbarium of the New 
England Botanical Club are cited below: 
LABRADOR: springy banks and damp hillsides, Forteau, July 30, 
1910, M. L. Fernald & K. M. Wiegand, no. 3,347. NEWFOUNDLAND: 
1For notes on the variations in the size and proportions of the floral parts, see Woodward, 
R.W.: Raopora xv. 209-10 (1913). 
