92 YELLOW WOOD SORREL. 



The J^rmt 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 

 regrna 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 PLAN" (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 |he Oxalides to the Gerania. 

 Their flowers are completely 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 dehiscence. Leaflets. Monadelphous. 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, displaj^ng some 300 

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

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



