136 LYTITRACEAE 



8. V. pratlncola Swamp Violet. Often 8'-10' high at flowering 

 time, glabrous : leaves as wide as long : sepals glabrous : petals bright 

 blue : peduncles of cleistogaraous flowers spreading. — Wet prairies 

 throughout especially in the southern part. Locally common. April- 

 May. 



2. CUBELIUM Raf. 



Caulescent leafy herbs with axillary greenish flowers borne on short 

 recurved pedicels. Lower petal slightly spurred at base. Stamens syn- 

 genesious. 



1. C. concolor (Forst.) Raf. Green Violet. 1°-2° high, pubes 

 cent : leaves oblong-lanceolate, tapering at both ends, petioled, nearly 

 entire. — Occasionally in rich woods throughout. April-May. 



Family 87. LOASACEAE Reichenb. 

 Herbs with alternate, non-stipulate leaves and cymose regular and per- 

 fect flowers. Calyx-tube adnate to the ovary, its limb 4-5-lobed. Petals 

 4-5, inserted with the numerous stamens on the calj'x throat. Ovary 

 1-celled, with 2-3 parietal placentae. 



1. MENTZELIA L. 



Characters of the family. 



1. M. oligosperma Nutt. Stick Leaf. 1°-3° high : leaves ovate to 

 oblong, short-petioled, coarsely dentate, very sticky, rough-pubescent : 

 flowers yellow, 10^^ broad, diurnal : stamens 20-30. — On limestone banks. 

 Dodson, Adams, Tarsney, Lee's Summit. Local. June-August. 



Family 88. CACTACEAE Lindl. 

 Plants with very much thickened and spiny stems. Leaves absent or 

 small and inconspicuous. Flowers sessile, solitary, large and showy. 

 Sepals, petals and stamens numerous. Ovary inferior, 1-celled, with 

 numerous ovules. Fruit a berry. 



1. OPUNTIA Mill. 



Stems branching, jointed. Leaves awl-shaped, deciduous, bearing 

 bristles and spines in their axils. Flowers yellow, opening in sunshine. 



1. O. humifusa Raf. Prickly Pear. Prostrate spreading : joints 

 obovate, '.V-'/ long, 2'-3' wide: spines white, 6^^-18^^ long, 1-4 to- 

 gether : bristles reddish-brown : fruit not spiny. — Rather common in 

 rocky places and barrens throughout the southern part. June. 



Family 89. LYTHRACEAE Lindl. 

 Herbs with opposite (except in Lytkrum) non-stipulate leaves and 

 axillary flowers. Calyx gamosepalous, often bearing accessory teeth. 

 Petals and stamens inserted on the calyx. Ovary superior, 1-4-celled, 

 many-ovuled. Style one. Stigmas capitate or 2-lobed. 



