CARYOPHYLLACEAE (CHICK-WEED FAMILY) 93 



HH. Leaves linear, widest near the middle; seed smooth under hand lens. 

 W. E. S. longlfolla (long-leaved chickweed) 



FF. Petals none or much shorter than the calyx. 



I. Pedicels grouped in somewhat unbel-Iike clusters; capsule 6-8 mm. long. E. 



S. umbellata (umbel chickweed) 



II. Pedicels scattered, not in umbel-like clusters; capsule 3-4 mm. long. (See J.) 

 EE. Inflorescence bracts foliaceous. 



J. Leaves lanceolate. W. C. E. S. borealis (northern chickweed) 



JJ. Leaves ovate. • 



K. Sepals obtuse, hardly scarious-margieed; petals none. W. E. S. obtusa 



KK. Sepals acute, scarious-margined. 

 L. Petals exceeding the calyx, always present. W. S. humlfusa 



LL. Petals exceeded by the calyx, sometimes none. 

 M. Stem glabrous; sepals lanceolate; petals minute or none. W. C. E. 



S. crispa 

 MM. Stem pubescent, sepals ovate; petals none. W. C. S. washingtoniana 



CERASTIUM (Mouse-ear) 



Annual or perennial, moptly pubescent or hirsute. Flowers white, in 

 dichotomous terminal cymes. Sepals 5. Petals bifid to entire. Stamens 

 10. Styles as many as the sepals and opposite them, or fewer. Capsule 

 i-celled, often curved, valves twice as many as there are styles. Seeds 

 many, rough. — (Gk. keras = a horn ; referring to the shape of the pod.) 



A. Petals not longer than the sepals, always present. 



B. Perennial, flowering in summer and fall; pedicels longer than the calyx. W. E. 



C. vulgatum (common mouse-ear) 

 BB. Annual, flowering in spring; pedicels not longer than the calyx. W. C. E. 



C. viscosum (spring mouse-ear) 

 AA. Petals decidedly longer than the sepals, rarely none. 



C. Flowers 12-21 mm. wide; perennial. W. C. E. C. arvense (field mouse-ear) 

 CC. Flowers 4-6 mm. wide. 



D. Annual; calyx not scarious-margined nor hairy. E. C. nutans (powderhorn) 

 DD. Perennial; calyx scarious-margined, hairy. W. C. E. C. beerlnglanum 



SAGINA (Pearlwort) 



Annual or perennial, tufted or matted, low. Leaves subulate or fili- 

 form. Flowers small, whitish, pediceUed, terminal. Sepals 4-5. Petals 

 none, or entire to emarginate. Stamens as many as the sepals, or fewer, or 

 twice as many. Ovary i-celled. Capsule 4-5-valved, opening at base. 

 Seeds many. — (L. sagina = fattening ; first the name of Spergula, with 

 fleshy leaves.) 



A. Herbage glabrous. 



B. Annual; stems decumbent, several-flowered, the lower flowers lateral; flowers 



1-3 mm. wide. W. C. E. S. occldentalis 



BB. Perennial; stems either erect, or else with a single terminal flower; flowers 



i~S mm. wide. 



C. Stems decumbent, filiform, i-flowered, the flower terminal; pedicels at length 



nodding. C. E. S. saglnoides 



