2(1). Sepals united 1. Silene 



2. Sepals free (3) 



3(2). Petals present (4) 



3. Petals absent (8) 



4(3). Petals more or less deeply bifid (5) 



4. Petals entire, emarginate or irregularly toothed (7) 



5(4). Style 1, 3-cleft; capsule 3-valved 2. Drymaria 



5. Styles 3 or more; capsule opening by twice as many valves or teeth as there 



are styles (6) 



6(5). Styles 5 3. Cerastium 



6. Styles 3 (or varying from 3 to 6) 4. Stellaria 



7(4). Fewer styles (2 or 3) than sepals 5. Arenaria 



7. As many styles as sepals (4 or 5) 6. Sagina 



8(3). Leaves linear 6. Sagina 



8. Leaves not linear 4. Stellaria 



1. Silene L. Catchfly. Campion 



About 500 species of wide geographic distribution, especially the Mediterranean 

 region. 



1. Silene acauiis L. var. subacaulescens (Williams) Fern. & St. John. Moss cam- 

 pion. Fig. 436. 



Pulvinate perennial from a woody root and a branched caudex, forming dense 

 mats to 3 dm. across; stem mostly 3-6 cm. tall, rarely more; leaves mostly basal, 

 sessile, marcescent for many years, linear to linear-lanceolate, 4-10 (-15) mm. 

 long, 0.8-1.5 (-2) mm. wide, glabrous to scabrous; flowers solitary, from essen- 

 tially sessile in the rosettes to stalked with peduncles to 4 cm. long, perfect or 

 frequently imperfect and the plants dioecious; calyx tubular-campanulate, (6-) 

 7-10 (-11) mm. long, 10-nerved, commonly pinkish; corolla pink to lavender or 

 rarely whitish; petals with a claw about twice as long as the blade, oblong- 

 oblanceolate, 8-12 mm. long, rounded to slightly emarginate at apex; appendages 

 usually 2, to about 1 mm. long or reduced to callosities or sometimes lacking; 

 carpophore 1-2 mm. long, sparsely pubescent; styles 3; capsule 3-celled; seeds 

 light brown, weakly papillate, about 1 mm. long. 



In wet soil of alpine slopes and meadows, often about rocks and in rock 

 crevices in N.M. (Colfax, Mora and Taos cos.) and Ariz. (Coconino Co.), 

 June-Sept.; the species as a whole circumpolar and alpine in both hemispheres. 



2. Drymaria R. & S. Drymary 



A genus of about 50 species, primarily American. 

 1. Drymaria pachyphyila Woot. & Standi. Fig. 436. 



Glaucous subsucculent annual, the vegetative branching largely confined to 

 radially diverging branches from a slender yellowish rootstock or to terminal 

 pseudoverticillate branch systems, the elongate spreading internodes much- 

 exceeding the terminally crowded leaves; leaves pseudoverticillate, with clasping 

 petioles to 8 mm. long, glaucous, subsucculent, wrinkling in drying, broadly 

 elliptic to suborbicular, obtuse to acutish at apex, tapering to the petiole, to 

 14 mm. long and 12 mm. broad; stipules absent; inflorescences of terminal and 

 axillary contracted umbelloid verticils subtended by normal foliage leaves and 

 bracts, the pedicels 1-5 mm. long; bracts ovate, obtuse, scarious and almost 

 nerveless, to 1.5 mm. long; sepals subequal, glabrous, glaucous, ellipsoid, obtuse, 

 to 3.3 mm. long and 2 mm. broad, obscurely 3- to 5-nerved, the central portion 

 green, the margins scarious; petals 5, 2.5-3 mm. long, bifid about half their 



887 



