83. Onagraceae 165 



5. Petals 1-3 mm wide; adv. from the northeast; Boone, 



Christian, and McHeni-y^ counties. Jime-July 



O. cruciata Nutt. 



5. Petals more than 3 mm wide. 



6. Plants green; free tips of sepals 3 mm long; roadsides, 

 fields, and waste places, vei-y common. June-Oct. 

 Common Exening-primrose \0. cymbatili.s Bartlett] 



(). biennis L. 



6. Plants canescent ; free tips of sepals 2 mm long; road- 

 sides and fields, occasional; adv. from w. of the 

 Mississippi R. Aug. [O. biennis var. canescens 



T. & G. ; O. canovirens Steele] 



O. strigosa (Rydb.) Mack. & Bush 



4. Capsules linear-cylindrical, 2-3 mm thick. 



7. Upper and median lea\es remotely denticulate to entire; 

 flowers many, in a terminal raceme; petals 12-25 mm 

 long, rhombic-ovate; capsules 1-2 mm long, strigose; 

 sandy soil, local; chiefly in the n. half of 111., but ex- 

 tending southward near the Mississippi R. to Pulaski 



Co. June-Sept O. rhombipetala Nutt. 



7. Upper and median leaves sinuately dentate or pinnatifid; 

 flowers few, axillary; petals 5-12 mm long, obovate; 

 capsules 2-3 cm long, pilose; sandy soil, locally 

 throughout 111. [Rairnannia laciniata (Hill )Rose; O. 



sinuata L.] O. laciniata Hill 



2. Calyx-lobes erect or ascending, cohering in pairs; stamens un- 

 equal in length, the alternate ones somewhat longer; flowers 

 diurnal; capsules 4-angled; plants perennial. 

 8. Petals yellow; capsules 4-winged; leaves entire or denticulate. 

 9. Stem erect; petals 1-3 cm long; capsules 1.5-2 cm long. 

 10. Petals 1-3 cm long; buds and inflorescence erect, not 

 nodding. 

 1 1 . Stem pilose ; capsules sparsely pilose, the hairs 

 glandless; leaves elliptical-lanceolate, hirsute on 

 both surfaces; roadsides and fields, not infrequent. 

 June-Oct. Common Sundrops [O. pratensis 



(Small) B.L.Robins.] O. pilosella Raf. 



1 1 . Stem short-pubescent; capsules with a few gland- 

 tipped hairs; leaves linear-oblanceolate, strigose; 

 di7 soil, rare; Johnson, Pidaski, and Saline coun- 

 ties. [O. fruticosa sensu auth.. non L.j 



- O. tetragona Roth 



10. Petals 5-10 mm long; buds and tip of inflorescence nod- 

 ding; stem strigose; cliy soil, not common; Cook and 

 Winnebago counties. June- Aug. Small Sundrops [O. 



pumila L.] O. perennis L. 



9. Stem decumbent, strigillose; petals 5-7 cm long; hypan- 

 thium 5-15 cm long; capsules 5-8 cm long, 4-6 cm wide; 



