166 American Midland Naturalist Monograph No. 7 



sandy or rocky soil, rare; St. Clair Co., Mulford in 1895. 



{Megapteriurn missouriense (Sims) Spach] 



O. missouriensis Sims 



8. Petals white or pink, 2.5-4 cm long; buds nodding; capsules 

 4-angled and ribbed, canescent-strigose, stipitate; leaves 

 dentate to pinnatifid, puberulent; roadsides, occasional; 

 native w. of the Mississippi R. June-July. White Evening- 

 primrose [Hartinannia speciosa (Nutt.) Small] 



O. speciosa Nutt. 



1. Stem-leaves linear-filiform; stigma shallowly lobed; petals 3-4 mm 

 long; capsules ellipsoid, sessile, 4-angled, 4-6 mm long; sandy 

 soil, usually on bluffs, locally in s. 111. May-June. [Kneiffia Uni- 

 folia (Nutt.) Spach; Peniophyllum linijolium (Nutt.) Pennell; 

 Stenosiphon linijolium (Nutt.) Britt.] O. linijolia Nutt. 



5. Gaura L. — Butterfly-weed 

 1. Ovary and fruit on pedicels 1-3 mm long; dry hillsides, rare; 



Hardin Co G. filipes Spach 



1. Ovary and fruit sessile. 



2. Petals 7-9 mm long; anthers linear, attached near the base; 

 fruit 4-angled, pubescent, 5-6 mm long; roadsides, fields, and 



open woods. July-Sept G. biennis L. 



2. Petals 2-3 mm long; anthers oval, attached near the middle; 

 fruit fusiform, 4-nerved, glabrous, 6-8 mm long; roadsides, 

 rare; adv. from w. U.S. June-July G. parviflora Dougl. 



6. Circaea L. — Enchanter's-nightshade 

 1. Stem 30-60 cm tall; leaves shallowly undulate-dentate, usually 



rounded at the base; fruit 2-loculed, 4 mm long at maturity; 



woods, common. June-July. [C. lutetiana sensu auth., non L.] 



C. latijolia Hill 



1. Stem 10-30 cm tall; leaves sharply dentate, mostly cordate; fruit 



1-loculed, 2 mm long; moist banks and ravines in deep woods; 



Lake Bluflf, Lake Co., E. ]. Hill: Elgin, Kane Co., Vasey; 



Jo Daviess Co., Pepoon & Mofjatt. June-July C. alpina L. 



84. Haloragaceae Horan. — Water-milfoil Family 



1. Leaves whorled (rarely subopposite or alternate), at least the immersed 

 ones pinnately dissected; stamens 4-8; fruit 4-lobed 1. Myriophyllum 



1. Leaves alternate, dentate or pectinate-pinnatifid ; stamens 3-4; fruit 3- 

 angled 2. Proserpinaca 



1. Myriophyllum L. — Water-milfoil 

 1. Carpels rounded and smooth on the back. 

 2. Floral leaves (bracts) entire or denticulate. 



3. Leaves verticillate in fours or fives; lakes and slow streams, 



