CARYOPHYLLACEAE. 149 



185. ARENARIA. SAND WORT. 



Annual or perennial mainly tufted herbs; leaves sessile, often 

 subulate and more or less rigid; stipules none; flowers white, 

 cymosely panicled or capitate, rarely solitary and axillary; 

 sepals 5; petals 5, very rarely minute or wanting, entire or 

 emarginate, white or nearly so; stamens 10, or often fewer; 

 styles generally 3, rarely 2-5; capsule globose or oblong, dehiscent 

 at the apex by as many or twice as many valves as there are styles. 



Leaves not narrowly linear nor rigid. 



Perennial; leaves linear or lance-linear; stems and foliage 



weak and flaccid. A. palndicola. 



Annuals; leaves lanceolate or ovate; stems and foliage 



not weak and flaccid. 



Leaves ovate; capsule flask-shaped. A. serpyllifolia. 



Leaves lanceolate; capsule oblong. A. leptoclados. 



Leaves narrowly linear, firm or rigid. 

 Sepals obtuse. 



Leaves glandular-hirsute; capsule-valves entire. A. sajanensis. 



Leaves glabrous or nearly so; capsule-valves 2- 



cleft. A. capillaris. 



Sepals acute or cuspidate. 



Plants loosely or not at all matted; cymes dichot- 

 omously branched, several to many-flowered; low- 

 land plant. A. tenella. 

 Plants densely matted or tufted, alpine; cymes few- 

 flowered. 

 Sepals not strongly nerved; petals shorter than 



the sepals. A. nuttallii. 



Sepals strongly nerved ; petals equalling the sepals. A . verna. 



Arenaria paludicola Robinson. Perennial, glabrous, the weak stems pro- 

 cumbent, shiny, angled, 15-30 cm. long; leaves sessile, and somewhat connate, 

 linear to linear-lanceolate, acute, 1-nerved, flat, 2-4 cm. long, the upper not 

 reduced; flowers solitary, axillary; sepals elliptic, subacute, 3-4 mm. long, 

 nerveless; petals obovate, twice as long as the sepals; capsule oblong, shorter 

 than the calyx. 



In swamps near Tacoma, Flett; otherwise known only in California. 



Arenaria serpyllifolia L. Annual, much branched, very leafy, puberulent 

 throughout, 5-15 cm. high; leaves ovate, cuspidately acute, 10-15 mm. long, 

 sessile or nearly so; uppermost leaves but little reduced; pedicels longer than 

 the calyx; sepals ovate-lanceolate, acute, 3-5-nerved; capsule flask-shaped. 



In dry soil; introduced from Europe. 



Arenaria leptoclados Guss. Very similar to A. serpyllifolia; stems slender, 

 erect; leaves lanceolate, the uppermost reduced to bracts; capsule oblong. 



Introduced from Europe. 



Arenaria sajanensis Willd. Perennial, densely cespitose; stems decumbent, 

 2-6 cm. high, glandular-hirsute, the dead leaves persistent; leaves linear, 

 firm, rather obtuse, 4-7 mm. long, glabrous or minutely glandular; flowers 

 mostly solitary; sepals narrowly oblong, obtuse, much longer than the spatulate 

 obtuse petals; capsule oblong, longer than the calyx. 



At high altitudes in the mountains. 



Aj-enaria capillaris pardifolia (Ledeb.) Regel. Perennial from a branching 

 caudex, the stems 10-20 cm. high; leaves mostly basal, crowded, linear, sharp- 



