24 



NATURAL HISTORY OF PLANTS. 



Oxalis violacect. 



In the inner angle of each cell is a placenta supporting one, two, 

 or an indefinite number of descendent, anatropous ovules with 

 exterior and superior micropyle, disposed at first in two vertical 

 series'. The fruit, generally accompanied by the persistent calyx, 

 is a loculicidal capsule, the pericarp remaining after dehiscence 



adhering to the axis of the fruit,^ 

 By the clefts of dehiscence escape 

 a very variable number of seeds con- 

 taining, under their triple coat,^ a 

 fleshy albumen, the axis being occu- 

 pied by a straight embryo. The 

 outer coat, thick and fleshy,* opens at 

 maturity (fig. 61) and separates from 

 the ianei* parts of the seed elastically 

 throwing them to a distance. This 

 genus contains at least two hundred 

 species,^ natives especially of South 

 Africa and the tropical and temperate 

 regions of South America. There 

 are some half dozen species widely 

 dispersed, some in the tropical, others 

 in. temperate regions of the whole 

 world. They are herbs, undershrubs 

 or shrubs of small size. The leaves 

 are alternate, petiolate, compound-pin- 

 nate or digitate, trifoliate or formed of a large number of articulate 

 folioles," entire or bilobate, more rarely reduced to a single foliole. 



Fig. 64. Habit. 



1 They have two coats. The exostome is often 

 prolonged into a more or less thick tube some- 

 times capped hy an ohturator. 



2 In Biophytiim (fig. 67) the valves of the 

 fruit always expand into the form of a star. 



* The deep layer is membraneous and whitish. 

 The middle layer is thick, crustaceous, of dusky 

 colour. 



* Formed of whitish cellules or rarely of 

 tracheal bundles. 



sjAca. Oxalid. Man. Vindob. (1794), in-4. 

 —Eeiohb. Ic. Fl. Germ. v. t. 199. — Zucc. in 

 Denks. Ah. Miinoh. ix. (1825), t. 1-6 ; in Abh. 

 Milnch. i. (1831), 1. 1-3.— H. B. K. Nov. Oen. et 

 Spec. V. t. 466-471.— A. S. H. PL Us. Bras. i. 

 104, t. 43-45 ; Fl. Bras. Mer. i. 104, t. 21-25.— 

 C. Gat, Fl. CMl. i. 122.— Gkiseb. Cat. PI. 2 Cub. 



47 ; Fl. Brit. W. Iitd. 133.— A. Gkay Man. ed. 

 5, 109.— Chapm. Fl. S. Unit. St. 63.— Hook. r. 

 Fl. N. Zel. t. 13 ; Man. 38.— Benth. Fl. 

 Austral, i. 300 ; Fl. Songkong. 66. — ^Wight, 

 Icon. t. 18; III. t. 62 {Biophytum). — Thw. 

 Fnum. PI. Zeyl. 64, 409.— Boiss. Fl. Or. i. 866. 

 — Oliv. Fl. Trap. Afr.; i. 295.— Harv. et 

 SoND. Fl. Cap. ; i. 313. — Gren. et Godr. Fl. 

 de Fr. i. 325.— Bot. Mag. t. 155, 237, 4490, etc. 

 — Walp. Mep. i. 476 ; ii. 821 ; v. 383; Ann. i. 

 147 ; ii. 240 ; iv. 399 ; vii. 495. 



^ It is one of the differences between the true 

 Oxalis and Biophytmn that the leaves of the 

 latter are paripinnate, with numerous folioles, 

 articulated and endowed with gentle movements 

 under the influence of Ught, darkness, shocks ; 

 in fact, nearly the same conditions as in Mimosa. 



