146 CARYOPHYLLACEAE. 



181. CERASTIUM. Mouse-ear Chickweed. 



Annual or perennial, generally pubescent or hirsute herbs; 

 leaves flat, rarely subulate; stipules none; flowers in terminal 

 bracted dichotomous cymes; sepals 5; petals 5, retuse or bifid, 

 very rarely subentire, white; stamens 10, sometimes fewer; 

 styles 5, sometimes 4 or 3, opposite the sepals; capsule cylindric, 

 1-celled, often curved, dehiscent by 10, rarely 8, apical teeth. 



Petals decidedly longer than the sepals. C. arvense. 

 Petals not longer than the sepals. 



Pedicels longer than the calyx. C. viilgatiim. 



Pedicels not longer than the calyx. C. viscosuni. 



Cerastiiun arvense L. Perennial, tufted, pubescent throughout or some- 

 times nearly glabrous; stems weak, erect, 15-40 cm. tall, nearly naked above; 

 leaves linear or lanceolate, 2-3 cm. long; flowers cymose, on slender pedicels; 

 sepals oblong, acute, 5-6 mm. long; petals deeply notched, twice as long as the 

 sepals. 



In dry open ground; common and variable. 



Cerastium vulgatxun L. Perennial, viscid-pubescent throughout, tufted 

 10-30 cm. high; leaves oblong, obtuse, or the upper ones acutish, 10-25 mm. 

 long; inflorescence loose, the pedicels longer than the calyx; sepals obtuse, 

 4-5 mm. long, as long as the 2-cleft petals; capsule somewhat curved, longer 

 than the calyx. 



A weed in lawns and pastures; introduced from Europe. 



Cerastium viscosum L. Annual, viscid-pubescent, erect or nearly so, 

 10-20 cm. high; leaves oval to ovate or obovate, very obtuse, the lowest 

 narrowed into short-margined petioles; inflorescence rather close in flower, 

 looser in fruit; sepals acute, 3-4 mm. long; petals shorter than the sepals. 



A weed introduced from Europe. 



182. STELLARIA. Chickweed. 



Annual or perennial tufted generally diffuse herbs; leaves flat, 

 rarely subulate; stipules none; flowers solitary or cymose, terminal 

 or becoming lateral ; sepals 5 or 4 ; petals 5 or 4, rarely none, always 

 more or less deeply bifid, often divided almost to the base, white; 

 stamens 3-10; styles 3 or 4, rarely 5; capsules globose, ovoid or 

 oblong, dehiscing by as many valves as there are styles. 



Lowest leaves ovate, pctiolate. 



Stems pubescent with a line of hairs; leaves ovate. S. media. 



Stems glabrous, except at base; leaves shiny, the up- 

 per linear-lanceolate. S. nitens. 

 Leaves all sessile. 



Bracts of the inflorescence small, scarious. 



Pedicels erect; cyme few-flowered. 5. longipes. 



Pedicels spreading; cyme loosely many-flowered. 



Leaves linear, acute at each end ; seeds smooth. 5. longifolia. 

 Leaves lanceolate, broadest near the base; seeds 



rough. S. graminea. 



Bracts of the inflorescence leafy. 



Leaves lanceolate. 5. borealis. 



Leaves ovate. 



Herbage glabrous. 5. crispa. 



Herbage finely puberulent. S. washingtoniana. 



