40 Spring Flora of Ohio. 



Ce-ras'-ti-um vis-co'-sum L. Mouse-ear Chickweed. — Nearly erect, 

 4-9 in. high, flowers small ; pedicels in fruit not longer than the 

 acute sepals; petals shorter than the calyx. 

 A. Leaves linear, lanceolate or oblong. 



Ce-ras'-ti-um vul-ga'-tum L. Larger Mouse-ear Chickweed. — Stems 



spreading; leaves oblong; flowers larger (sepals ■!-?> lines long) the 

 earlier fruiting pedicels much longer than the obtuse sepals; petals 

 equalling the calyx. 



Ce-ras'-ti-um lon'-gi-pe-dun-cu-la'-tum Muhl. [C. nutans Raf.) Nod- 

 ding Mouse-ear Chickweed. — Stems slender, erect, grooved, difl"usely 

 branched, (1-20 in. high; leaves oblong-lanceolate ; petals longer than 

 the calyx; pods nodding on the stalks, curved upward, thrice the 

 length of the calyx. 



Ce-ras'-ti-um ar-ven'-se L. Field Chickweed. — Stems ascending or 

 erect, tufted, 4-8 in. high, naked and few-flowered at the summit; 

 leaves linear or narrowly lanceolate, petals obcordate, more than twice 

 the length of the calyx; pods scarcely longer than the calyx. 



Ce-ras-'ti-um ar-ven'-se ob-lon-gi-fo'-li-um (Torn) Britt. Mouse-ear 

 Chickweed.— Like the last, but usually taller, leaves narrowly or broadly 

 oblong or oblong-lanceolate, and pod about twice longer than the calyx. 



4. Genus AR-E-NA'-RI-A.— Sepals .< (rarely 4); petals 5 (rarely 4), 

 entire or barely notched, rarely wanting; low plants with sessile 

 leaves. 



Ar-e-na'-ri-a ser-pyl-li-fo'-li-a L. Thyme-leaved Sandwort. Leaves ovate, 

 acute, small ; plant "J-lj in. high. 



Ar-e-na'-ri-a lat-er-i-flo'-ra L. Sandwort. Parts of the flower some- 

 times in fours; leaves oval or oblong, ^4-1 in. long; plant erect, 

 branched. 



5. Genus SPER'-GU-LA. — Sepals, petals and styles each 5, stamens 

 5 or 10; pod 5-valved, leaves in whorls. 



Sper'-gu-la ar-ven'-sis L. Corn Spurry. — Leaves numerous, thread- 

 shaped, 1-2 in. long, whorled. 



6. Genus TIS'-SA. [Biida.) — Sepals 5, petals 5, entire, stamens 

 2-10, styles and valves of pod 3 (rarely 5) ; leaves linear, opposite. 



