56 KEY AND FLORA 



a. C. arven'se L: Perennial, with spreading stems. Leaves 

 linear-lanceolate, clasping the stem. Flowers in. in diameter, on 

 long pedicels, in few-flowered cymes. Capsule extending but little 

 beyond the calyx. Common around San Francisco and northward. 



b. C. visco'sum L. * Annual, somewhat clammy, branched from 

 the base. Leaves small, generally ovate. Flowers on short pedicels 

 in rather close cymes. Petals shorter than the calyx. Capsule nearly 

 straight, much longer than the calyx. The flowers open only in sun- 

 shine. This is an introduced weed. 



m. STELLA'RIA, Chickweed 



This is similar to Cerastium, but the petals are %-lobed, and 

 the capsule is globose., dehiscent to below the middle. 



a. S. me'dia L. CHICKWEED. Annual, spreading and rooting 

 at the lower joints. Leaves ovate, petioled. Flowers small, on slen- 

 der pedicels, ivhich are defl.exed in fruit, in the axils of leafy bracts. 

 Stamens 3-10. Pod equaling or surpassing the calyx. This is 

 introduced, and is very common in shady, damp places. 



b. S. ni'tens Nutt. Annual, low, with slender, shining stems. 

 Flowers small, erect, on short pedicels. Sepals shining, 3-nerved, 

 twice as long as the petals, which are sometimes wanting. Pod shorter 

 than the calyx. This is a delicate little plant, with inconspicuous 

 flowers blooming in early spring and soon disappearing. 



c. S. cris'pa Ch. & Schl. Smooth, with long, weak, trailing stems. 

 Leaves thin, ovate, about an inch long, with crisped margins. Flowers 

 axillary, on slender pedicels. Sepals lanceolate, 3-nerved. Petals 

 small, or wanting, white. Capsule when ripe longer than the sepals. 

 Northern California to Alaska, growing in wet, shady places and 

 blooming in spring and summer. 



d. S. borea'lis Bigel. Generally smooth and erect, 6-10 in. in 

 height. Leaves lanceolate, narrowed to a long point, - 1^ in. long, 

 with one prominent nerve. Pedicels often deflexed, scattered. Sepals 

 ovate-lanceolate with papery margins, acute or obtuse. Petals 

 shorter than sepals or wanting. Pods narrow, acute, nearly twice as 

 long as the sepals. Seeds smooth. Northern California to Wash- 

 ington. Blooming in summer. 



IV. ARENA'RIA, Sandwort 



Sepals separate. Petals 5, ivhite, entire or notched. Sta- 

 mens 10. Styles 3. Pod splitting into 3 valves, each with 

 2 parts. 



