44 



NATURAL HISTORY OF PLANTS. 



lAnum perenne. 



five alternipetaloTis glands ^ The gyneeceum is composed of a free 

 superior ovary, surmoTinted by a style soon divided into five branches 

 superposed to the petals, with linear apex, elongated or capitate, bear- 

 ing stigmatic papillae. The ovary contains an equal number of oppo- 



sitipetalous cells, in the internal angle of 

 which a placenta is seen supporting two 

 collateral, descending, anatropous ovules, 

 with exterior and superior micropyle,^ 

 capped by an obturator springing from 

 the placenta above each ovule. From the 

 outer wall of- each cell or the midrib a 

 false partition is produced which advances 

 more or less between the two collateral 

 ovules and may even reach the placenta, 

 and so isolate each ovule in a compart- 

 ment representing a half cell. The fruit, 

 generally accompanied by the persistent 

 calyx, is a septioidal capsule which divides into five dispermous pieces 

 or into ten monospermous ones, when the false partition divides at 

 maturity. The seeds contain, under their triple coat,^ a fleshy 

 albumen, often inconsiderable, surrounding a fleshy straight embryo, 

 with superior radicle. The Plaxes are annual or perennial herbs, 

 or suff'rutescent plants, with simple entire leaves alternate or rarely 

 opposite, sometimes accompanied by two small glanduliform stipules. 

 The flowers * are united in terminal or axillary cymes, sometimes 

 biparous and more or less regular in their lower parts, sometimes 

 uniparous and resembling more or less contracted or elongated 

 Some twenty-four species have been described,^ natives 



Fig. 76. Inflorescence. 



racemes. 



' Often but very little noticeable. 



' With double coat. 



' Three principal layers are distinguished ; 

 one an interior membrane, thin brownish rather 

 tough surrounding the albumen ; more out- 

 wardly a tissue also brown, paler, and stronger 

 than, the first from which it easily separates ; 

 and outside a white layer remarkable for the 

 way in which it acts when brought into con- 

 tact with water to form mucilage. As soon as 

 it is touched by the liquid it thickens rapidly, 

 all the cells without separating rise parallel to 

 each other, the common partitions riae without 

 separating in an instant. Later the action of 



the liquid brings about a thickening, softening, 

 and even an unequal breaking of the walls, etc. 



^ White, yellow, pink, red, or blue. They 

 are often dimorphous, with two forms, one with 

 long the other with short style, being much 

 more fruitful it is said, when fertilized mutually 

 than when alone, attention having first been 

 drawn to this fact by Dabwin in his work : 

 " On the existence of two forms and on their reci- 

 procal sexual relation in several species of the 

 genns Linum " (in Journ. Linn. Soc. vii. 69). 



« Sm. Brit. Fl. i. 342 j ISxot. 17.— JAca. Fl. 

 Austr. t. 31, 215, 321, 418.— Eeichb. Ic. Fl. 

 Germ. vi. t. 325-341.— WALDSL.et. Kit. PI. 



