190 American Midland Naturalist Monograph No. 2 



4. Hypanthium conspicuously extended beyond the ovary into a tube 



4. Oenothera 



2. Fruit indehiscent, deciduous; flowers pink 5. Caiira 



1. Flowers with 2 notched white petals, 2 sepals, and 2 stamens; fruit indehiscent, 

 obovoid, with hooked bristly hairs 6. Circaea 



1. Epilobium L. — Willow-herb 



1. Petals 1-2 cm. long; stigma 4-Iobe(d; edges of woods and burned-over 

 ground, local; known from Lake, McHenry, Cook, and La Salle counties. 



June-Aug. Fireweed [Chamaeiierion spicatum (Lam.) S. F. Gray} 



E. angustifolium L. 



1. Petals 3-8 mm. long; stigmas entire. 

 2. Leaves lanceolate, denticulate. 



3. Seeds beakless, 1-1.5 mm. long; coma reddish brown; moist ground, 

 local. Aug. -Sept E. coloration Muhl. 



3. Seeds short-beaked, 0.5-1 mm. long; coma whitish; moist ground, not 



common; chiefly in the n. and w. parts of the state. July-Sept 



E. adenocaulon Haussk. 



2. Leaves linear, or linear-lanceolate, mostly entire. 



4. Stems, leaves, and capsules copiously soft-pubescent with short, straight 



hairs; leaves mostly 4-8 mm. wide; petals 7-8 mm. long; seeds 2 mm. 

 long; wet ground, rare. Lake Co., Gleason & Shobe 162; Woodford 

 Co., June 1889, McDonald; McHenry Co., Vas^y. July-Sept. [£. 



niolle sensu Torr., non Lam.; E. dcnsiim Raf.] E. strictum Muhl. 



4. Stem, leaves, and capsules crisp-puberulent; leaves 1-4 mm. wide; petals 

 3-5 mm. long; seeds 1.5 mm. long; wet ground, rare; known from 

 Lake, Peoria, and Mason counties. Aug. -Sept. \_E. Imeare Muhl., 



nom. illegit.; E. densiirn sensu auth., non Raf.] 



E. leptophyllum Raf. 



2. JussiAEA L. — Primrose-willow 



1. Plants creeping or floating; petals 5; capsule cylindrical; leaves elliptical, 

 tapering to a slender petiole; muddy banks, or in water, not common; 

 chiefly s. 111. July-Aug /. diffusa Forsk. 



1. Plants erect; petals 4; capsules clavate, 4-angled; leaves lanceolate, decur- 

 rent; wet ground, rare; s. III. July-Sept /. decurrens (Walt.) DC. 



3. LuDWiGiA L. — False Loosestrife 



1. Petals yellow, equalling or exceeding the sepals; leaves alternate; flowers 

 peduncled; capsules opening by terminal pores; swamps. June-Sept. Seed- 

 box _L. ahernjfolia L. 



1. Petals small, greenish, or absent; flowers sessile. 



2. Leaves opposite, ovate or oval; muddy shores and ditches, local. July- 



Aug. [Isnardia palustris L.] L. palnstris (L.) Ell. 



2. Leaves alternate. 



3. Capsules cylindrical; stem glabrous; bractlets minute; swamps, s. 111., 



rare. Massac Co. July-Sept L. glandulosa Walt. 



3. Capsules subglobose or turbinate; leaves lanceolate or linear. 



