GENUS 2. 



CHICKWEED FAMILY. 



6. Cerastium arvense L. Field or Meadow 

 Chickweed. Fig. 1768. 



Cerastium arvense L. Sp. PI. 438. 1753. 



Perennial, densely tufted, erect or ascending, 

 pubescent or nearly glabrous, flowering stems 

 simple or sparingly branched, 4-10' high. Basal 

 leaves and those of the sterile shoots linear- 

 oblong, close, slightly narrowed at the base; 

 stem-leaves distant, linear or narrowly lanceo- 

 late, 5"-is" long, i "-2" wide, acute; flowers 

 several, cymose, 6"-8" broad; pedicels slender, 

 erect; petals obcordate, much exceeding the 

 lanceolate acute sepals which equal or are a little 

 shorter than the slightly oblique pod. 



In dry, rocky places, Labrador to Alaska, south to 

 Georgia, Missouri, Nevada and California. Also in 

 Europe and Asia. April-July. 



7. Cerastium velutinum Raf. Barren Chick- 

 weed. Fig. 1769. 



C. velutinum Raf. Med. Rep. II. 5 : 359. 1808. 



C. oblongifolium Torr. Fl. U. S. 460. 1824. 



C. arvense villosum Holl. & Britt. Bull. Torr. Club 14 : 49. 



1887. 

 C. arvense oblongifolium Holl. & Britt. loc. clt. 47. 1887. 



Perennial, tufted, erect or diffuse, pubescent or vil- 

 lous; flowering stems 12' high or less. Leaves lanceo- 

 late to oblong or ovate-lanceolate, mostly obtuse, li' 

 long or less, 2"-$" wide, those of the flowering stems 

 distant; flowers several, cymose, 7"-io" wide; petals 

 obcordate, much longer than the sepals ; pod i2"-is" 

 long, about twice as long as the sepals. 



On serpentine and limestone rocks, New York to Mary- 

 land, southern Ontario, Minnesota and Colorado. May- 

 July. 



8. Cerastium alpinum L. Alpine Chickweed. 

 Fig. 1770. 



Cerastium alpinum L. Sp. PI. 438. 1753. 



Cerastium Fischerianum Ser. in DC. Prodr. i : 419. 1824. 



Cerastium alpinum Fischerianum T. & G. Fl. N. A. i : 188. 1838. 



Perennial, generally silky-hairy, sterile stems prostrate, 

 flowering stems erect, 2,' 12' high. Lower leaves somewhat 

 oblanceolate or spatulate, dense, 2"-4" long, obtuse ; upper 

 leaves distant, ovate-oblong, obtusish, 4"-8" long; flowers 

 solitary or 2-3, 6"-o/' broad ; pedicels slender ; petals 2-lobed, 

 twice the length of the lanceolate acute scarious-tipped sepals ; 

 pod longer than the calyx, nearly straight. 



In moist, rocky places Gaspe, Quebec ; Greenland, Labrador and 

 in arctic America to Alaska. Also in arctic and alpine Europe and 

 Asia. Consists of numerous races, differing in size of the plant, 

 size of the flowers, character and amount of pubescence. Summer. 



