92 YELLOW WOOD SORREL. 



The J^7'ZcU is an oblong capsule (7) made up of 5 car- 

 pels, each with a row of seeds in its cell (8). The carpels 

 open on the back {dorsal dehiscence) and do not separate 

 from the central axis (carpophore) at once as they do in the 

 regma of Geranium. The seed is anatropous (9), with a 

 loose, separable outer coat (10, 11) and a large straight em- 

 bryo buried in albumen (12). 



The Plaj^" (1) shows the sepals to be qidncuncial (p. 43) 

 and the petals contorted in aestivation. 



The Name of this plant, Oxalis [oxus, sour), refers to 

 the taste of the herbage given to it by the presence of oxalic 

 acid in the form of a salt (binoxalate of potash). The spe- 

 cific name, 0. stricta, alludes to its upright stem ; the other 

 species being mostly acaulescent. Oxalis is an admirable 

 genus, embracing in all lands 220 species, many of which 

 are beautiful conservatory and house plants.* 



Classification. — The student can hardly fail to notice 

 the striking resemblance of the Oxalides to the Gerania. 

 Their flowers are comiiletely analogous. The fruit in both 

 consists of 5 carpels--as many as the sepals, attached to a 

 central axis arising from the torus. Oxalis takes rank, 

 therefore, with the Gerania in the Order Geraniaceae. 



Scientific Terms.— Alternate. Axil. Axillary. Contorted. Con- 

 volute. Dorsal deliiscence. Leaflets. Monadelplious. Obcordate. 

 Palmate-trifoliolate. Pinnate-trifoliolate. Trifoliolate. Umbellate. 



* One of the most popular is O. floribunda (Lehmann) from Brazil. A specimen 

 growing in our study has bloomed five months continuously, displaying some 3 )0 

 roseate flowers on every sunny day. It is very exacting iu its vigils, closing its leaves 

 at sunset, and its flowers always except in the sunshine. 



