210 SUMMER FLOWERS. 



calyx ; seeds numerous, appearing beautifully ribbed and trans- 

 versely striated under the microscope. Water Pepper. Mar- 

 gins of pools under water. Fl. July, August. 



E. Hydropiper : annual ; differs from the last in having ses- 

 sile flowers, with four sepals, petals, and styles, and eight sta- 

 mens, a more deeply divided calyx, and fewer and larger seeds. 

 Margins of pools and in water. Fl. July, August. 



(59) Linum. FLAX. 



* Leaves scattered ; flowers ~blue. 



L. usitatissimum : annual ; stems 1-2 feet high, erect, gla- 

 brous, usually branched only at the top ; leaves alternate, 

 erect, narrow-lanceolate, pointed, entire ; flowers rich blue, in a 

 loose terminal corymb ; sepals pointed ; petals obovate ; capsule 

 globular or slightly depressed. Linseed. A weed of cultiva- 

 tion. Fl. July. 



L. perenne : stem 1-2 feet long, erect or decumbent ; very 

 variable, sometimes resembling the last, but the stems usually 

 more slender, the leaves smaller and narrower, and the sepals 

 obtuse. Dry limestone pastures. Fl. June, July. 



L. angustifolium : stem 1-2 feet high, branching irregu- 

 larly, decumbent; leaves narrow, linear-lanceolate; flowers 

 smaller than the preceding, pale blue, the sepals pointed 

 Limestone pastures and wastes. Fl. July. 



** Leaves opposite ; flowers wJtite. 



L. catharticum : annua 1 ; stems 3-8 inches high, slender, 

 erect, or slightly decumbent, glabrous ; leaves small, opposite, 

 obovate or oblong; flowers very small, pure white, on long 

 slender pedicels. Meadows and pastures. Fl. June to Au- 

 gust. 



