234 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Range: Washington and Oregon to California and northern New Mexico. 

 New Mexico: Vicinity of Tierra Amarilla (Eggleston 6478, 6543). Open slopes, 

 in the Transition Zone. 



49. ALSINACEAE. Chickweed Family. 



Low slender annuals or perennials, with opposite simple leaves and small white 

 flowers; inflorescence cymose or the flowers solitary and axillary; sepals 4 or mostly 5, 

 distinct, or slightly united at the base; petals not clawed, entire, emarginate, or 

 deeply cleft and parted, often wanting; fruit a capsule, dehiscing by longitudinal 

 valves. 



KEY TO THE GENERA. 



Stipules present though sometimes fugacious. 



Styles simple below 1. Drymaria (p. 234). 



Styles branched to the base 2. Tissa (p. 235). 



Stipules wanting. 



Petals 2-cleft or 2-parted . 



Capsules short-ovate or oblong; styles usually 3. . . 3. Alsine (p. 235). 

 Capsules long-cylindric, often curved; styles usu- 

 ally 5 4. Cerasttum (p. 236). 



Petals entire or emarginate. 



Styles as many as the sepals and alternate with 



them 5. S agin a (p. 238). 



Styles fewer than the sepals, or when of the same 

 number opposite them. 

 Seeds with a basal membrane (strophiole) at 



the hilum 6. Moehringia (p. 238). 



Seeds not strophiolate. 



Capsules with twice as many valves as 



styles 7. Arenaria (p. 238). 



Capsules with the same number of valves 



as styles 8. Alsinopsis (p. 240). 



1. DRYMARIA Willd. 



Low slender erect or prostrate annuals or perennials with inconspicuous flowers; 

 leaves with stipules, these sometimes fugacious; sepals and petals 5, divided; stamens 

 usually 5; capsule 3-valved. 



KEY TO THE SPECIES. 



Cauline leaves broadly ovate. 



Plants erect, glandular, bright green; leaves abruptly acu- 

 minate 1. D.fendkri. 



Plants prostrate, glabrous and glaucous; leaves obtuse 2. D. pachyphylla. 



Cauline leaves linear. 



Cauline leaves pseudoverticillate 3. D. sperguloides. 



Cauline leaves opposite. 



Plants tall, 10 to 15 cm., erect; sepals acute; pedicels usu- 

 ally several times as long as the calyx 4. D. tenella. 



Plants low, 4 cm. or less, depressed; sepals obtuse; pedi- 

 cels as long as the calyx or shorter 5. D. depressa. 



1. Drymaria fendleri S. Wats. Proc. Amer. Acad. 17: 328. 1882. 

 Type locality: New Mexico. Type collected by Fendler (no. 60). 

 Range: New Mexico and Arizona, southward into Mexico. 



