lO TRANS. ST. LOUIS ACAD. SCIENCE. 



Annual or perennial caulescent herbs or low shrubs. Leaves alternate^ 

 sometimes opposite or subverticillate below ; simple, generally entire^ 

 sessile or nearly so, mostly estipulate. Inflorescence usually cymose. 

 Flowers hermaphrodite, 4-5-merous, hypogynous. Sepals valvate. Petals^ 

 convolute, distinct or nearly so. Stamens as many as the petals and 

 alternate with them, monadelphous at the base, sometimes with inter- 

 mediate processes, persistent; anthers oblong, introrse, more or less 

 versatile, 2-celled, dehiscing longitudinally. Styles 2-5. Ovary slightly 

 4-10-lobed, its cells equal in number to the styles, or twice as many, from 

 the intrusion of a false partition from the back of each cell; the true cells 

 2-ovuled. Seeds oily, with a little albumen; embryo usually straight, 

 with plane cotyledons. Glands of the receptacle 5, mostly small, oppo- 

 site the sepals. — About 90 species, widely distributed. 



LiNUM, L., Gen. No. 389. Benth. & Hook. Gen. Plant, i. 242. — Leaves 

 estipulate, or with a pair of rounded glands occupying the place of stip- 

 ules. Flowers 5-merous, symmetrical except that the carpels are fewer 

 than the other parts in one section. Sepals persistent and at length 

 deciduous. Petals fugacious. Capsule splitting through the false septa, 

 and also septicidal in most species. — About 80 species, chiefly in temper- 

 ate regions. 



SYNOPSIS OF NORTH AMERICAN SPECIES. 



* Flowers large, blue; sepals not glandular-margined; carpels J, not cartilaginous at 

 base; styles distinct. 

 Annual; stigmas elongated ; false septa incomplete. 



Capsule rather short, not dehiscent, septa not ciliate L. usitatissimuni . 



Capsule longer, dehiscent; septa ciliate within L. humile. 



Perennial; stigmas not much longer than broad; capsule incompletely lo-celled, 

 widely dehiscent L. Leviisii. 



heterogony of several species) . Meehan : Bull. Torrey Bot. Club, 1S77, ^'- '§9 C-^- Lewisii) . 

 Muller: Befrnchtung der Blumen, 167; Weitere Beobachtungen, 219 (visitors of Z.. usita- 

 tissimum). Planchon : Hooker's Journ. Boi. 1848, vii. 174, 175 (flowers of X. sa I so ides a.nd 

 I,. Lewisii). Thomson: Trans. Bot. Soc. Edinburgh, xiv. 103 (Z,. monog^yntim) . Tre- 

 viranus : Bot. Zeit. 1863, xxi. 189 (note on heterostylism). Urban: Linnsea, neue Folge, 

 vii. 609 (South American species homogone) ; Verhandl. Bot. Ver. Brandenburg, 1881, 

 xxii. 18 (on Reinxvardtia). 



On the structure of tlie seed-coats of Linum see, among otiiers : Gartner : De Fruct. et 

 Semin. Plant ii. 146, pi. 112^ f. 11. Harz : Landwirtsch. Samenkunde, 950, f. So. Hilde- 

 brand : Bot. Zeit. 1872, 909. Hofmeister: Kon. Sachs. Ges. Naturwiss. 185S. 2D, pi. i. f. i. 

 Niigeli and Kramer: Pflanzenphysiol. Unters. 1-3, pi. 27, 2S. Nobbe : Handb. Samen- 

 kunde, 77,78, f. 81. Sempelowski : Beitr. z, Kenntniss des Baues der Samenschale. The- 

 sis, Leipzig, 1874, 3. pi. 1, f. 1-3. 



The germination of the fdtty seeds of flax is discussed by Jorissen : Bull. Acad, Roy .^ 

 Belg. 18S4, vii. 



