200 XXXI. OXALIDACE^E. OXALIS. 



TROP^OLUM. 



Lat. trop&um, a trophy ; the leaf resembles a shield, the flower an empty helmet. 



Character essentially the same as of the order. 



T. MAJUS. Nasturtion. Indian Cress. Lvs. peltate, roundish, repand on the 

 margin, with the long petiole inserted a little one side of the centre ; pet. ob- 

 tuse, the two upper distant from the 3 lower, which are fimbriate at base, and 

 contracted into long claws. Native of Peru. Stem at length climbing by 

 means of its long petioles several feet. Leaves a fine example of the peltate 

 form, about 2' diam. Flowers large and showy, orange-colored, with blotches 

 of deeper shade. They are eaten for salad. June Oct. 



ORDER XXX. LIMNANTHACE^). 



Herbs annual, with an acrid, watery juice. Lvs. alternate, pinnatifid. 



Stipules 0. Flou-ers regular. 



Ca/. Sepals 35, united at base, persistent, valvate in aestivation. 



Cor Petals 35, marescent, inserted upon an hypogynous disk. 



Sta. twice as many as petals and inserted with them. Filaments opposite the sepals, with a small pro- 



Ova. of 2 5 distinct carpels. Sty. united. Stig. simple. [cess outside the base. 



Fr 25 achenia, rather fleshy. Seeds solitary. 



Genera 2, species 3, mostly natives of the temperate parts of North America. They have no very 

 remarkable properties. Floerkea is the only northern genus. 



FLCERKEA. Willd. 



Named in honor of Floerke, a German botanist. 



Sepals 3, longer than the 3 petals ; stamens 6 ; ovaries 3, tuber- 

 culate, style 2-cleft. small, aquatic, with pinnately divided leaves. 



F. FROSERPiNACoiDEs. Lindl. (F. uliginosa. Muhl.) False Mermaid. 



Grows in marshes and on river and lake shores, Vt. to Penn. W. to Mo. 

 Stems decumbent, less than a foot in length, weak and slender. Leaves alter- 

 nate, upper ones, or those above the water, pinnately 5-parted, lower or sub- 

 mersed ones mostly 3-parted, all on slender petioles 1 3' in length. Flowers 

 axillary, pedunculate. Petals white, small, about half as long as the sepals. 

 Achenia large, 2 or 1, roundish. 



ORDER XXXI. OXALIDACEJE. WOOD SORRELS. 



St. low, herbaceous, with an acid juice, and alternate, compound leaves. 



Slip, rarely present. Fls. regular and symmetrical. 



CaL Sepals 5, persistent, equal, sometimes slightly cohering at the base. 



Cor. Petals 5, hypogynous, equal, unguiculate, deciduous, twisted in aestivation. 



Sta. 10, hypogynous, more or less monadelphous, those opposite the petals longest. 



Ova. Carpets 5, united, opposite the petals. 



Fr. capsular, usually membranous, 5-lobed and 5-celled. 



Genera 6, species 325, inhabiting hot and temperate regions. The stem and leaves generally contain 

 free oxalic acid. The order is represented in the Northern States by the following genus only. 



OXlLIS. 



Gr. ofu?, sour; from the acid taste of most species. 



Sepals 5. distinct or united at base ; petals much longer than the 

 calyx ; styles 5, capitate ; capsule oblong or subglobose ; carpels 5, 

 1 several-seeded. Mostly % with trifoliate kaves. 



1. O. ACETOCELLA. Common Wood Sorrel. 



Acaulescent ; scape longer than the leaves, 1-flowered ; Ifts. broad-obcor- 

 date, with rounded lobes ; sty. as long as the inner stamens ; rt. dentate, scaly. 

 Woods and shady places, Can. and Northern States. Leaves palmately 3-foli- 

 ate, on long, weak stalks, purplish beneath. Peduncles longer than the leaves, 

 each with a nodding scentless flower whose petals are white, yellowish at the 

 base, delicately veined with purple. The whole plant has an agreeable, acid 

 taste. Jn. 



