This species is distinguished from such species as C. hrochypodum and C. 

 vulgatum by having its flowers produced singly in leaf axils along much of the 

 main stem and branches instead of being produced in apical cymes as in those 

 species. The plant is also densely glandular-pubescent, and the small, deeply lobed 

 petals are conspicuously exceeded by the sepals. 



2. Cerastium vulgatum L. Common mouse-ear. Fig. 437A. 



Short-lived matted perennial with depressed basal leafy offshoots: flowering 

 stems to 65 cm. high, hirsute to rarely glandular, the median internodes becoming 

 as much as 12 cm. long; leaves of the season in 3 to 7 pairs, oblanceolate to 

 oblong or narrowly oval, conspicuously white-hirsute on both surfaces, the median 

 leaves to 4 cm. long and 15 mm. wide; bracts similar to leaves but smaller, 

 broadly scarious at summit and margin; inflorescences 3- to many-flowered, 

 forming terminal ultimately very dichotomous cymes, at first rather compact, in 

 fruit with the lower pedicels divergent or reflexed and 2 to 4 times the length 

 of the calyx; sepals 5-7 mm. long, ovate-lanceolate to elliptic-lanceolate, obtuse 

 to acute, scarious-margined, hirsute but glabrous at tip; petals 4-5 mm. long, 

 narrow, about equaling or rarely somewhat exceeding the sepals, cleft for about 

 1 mm. at apex, with ciliate claw; capsule narrowly cylindrical, curved, 9-12 mm. 

 long; seeds to 0.9 mm. in diameter, reddish-brown, bluntly tuberculate. C. triviale 

 Link. 



A nat. of Euras. that has become naturalized in fields, along roadsides, and 

 about old homesteads, also wet soil of stream banks and wet meadowlands, un- 

 common in Okla. {Waterfall) and Tex., w. to N. M. (Catron and San Miguel 

 cos.) and Ariz. (Apache, Navajo and Pima cos.), spring-summer; throughout 

 most of temperate N.A. 



The var. holosteoides Fries is a glabrescent plant or with minute lines of 

 hairs on the stems; the elliptic to oblong leaves are dark-green, ciliate and 

 round-tipped. 



3. Cerastium arvense L. Fig. 437B. 



Perennial, the stems tufted, erect or ascending, pubescent or nearly glabrous, 

 the flowering stems sparingly branched above, 1-4 dm. high; basal leaves subulate- 

 linear to linear-oblong, 1-4 cm. long, narrowed at the base, rather crowded, those 

 of the flowering stems distant and somewhat reduced; bracts similar to leaves but 

 smaller, scarious-margined; flowers loosely cymose, rather few; pedicels slender, 

 elongated, erect; sepals 4-7 mm. long, lanceolate, glandular-puberulent to 

 glandular-pilose, acute; petals obcordate, much-exceeding the calyx; capsule 

 globose to ovoid, only slightly longer than the sepals. 



In wet meadows at high elevations in N. M. and Ariz., June-July; Lab. to 

 Alas., s. to Ga., N. M., n. Ariz, and Calif.; introd. from Eur. 



4. Cerastium brachypodum (Engelm.) Robins. 



Annual, pale-green, finely pubescent or puberulent and sometimes viscid, to 

 about 3 dm. high, sparsely branched; leaves linear-oblong to oblanceolate, obtuse 

 to subacute, seldom more than 25 mm. long; flowers in more or less open dichot- 

 omous cymes; pedicels about equaling but sometimes shorter than or a little 

 exceeding the capsules, erect or somewhat deflexed, straight or at most gently 

 curved, not hooked below the calyx; calyx about 4 mm. long, the lobes elliptic 

 and acute, very sparsely glandular-puberulent; petals elliptic in outline, about 

 6 mm. long and 2 mm. wide, exceeding the sepals, notched for about 1 mm. at 

 the apex, the lobules triangular-lanceolate and acute; capsules 2 to 3 times as 

 long as the calyx. Incl. var. coinpactum Robins. 



891 



