184 American Midland Naturalist Monograph No. 2 



5. Flowers 4-6 cm. broad, the petals 2-2.5 cm. long; capsules 1.5-2 cm. 

 long; cyme few-flowered; stamens united into 5 sets; styles 5; 

 banks of streams, locally throughout III., except the s. counties. 



July-Aug. Giant St. John's-wort H. ascyron L. 



5. Flowers 1-2 cm. broad, the petals 6-10 mm. long; capsules 4-6 mm. 



long; stamens distinct. 



6. Stems somewhat woody at base; sepals oval or ovate-lanceolate, 



plane or nearly so; capsules unilocular, ovoid, 4-6 mm. long; 



seeds rugulose and pitted; roadsides, open woods, river banks, 



throughout 111. June-Aug. \H. cistifolium of auth., not Lam.} 



H. sphaerocarpum Michx. 



6. Stem herbaceous throughout, from a slender, creeping, stolonifer- 

 ous base; sepals lanceolate, the margins more or less revolute; 

 capsules incompletely 3-5-loculed by the projecting placentae; wet 



ground, s. 111., rare. July-Aug H. adpressum Bart. 



4. Petals black-dotted, at least along the margin. 



7. Flowers 1.5-2.5 cm. broad; petals black-dotted along the margin; 

 sepals lanceolate; leaves linear or oblong, 1-2 cm. long, 2-8 mm. 

 wide, numerous, pellucid-dotted; stem with numerous basal sterile 

 shoots; roadsides and fields, common; adv. from Eur. June-Aug. 



Common St. John's-wort H. perforatum L. 



7. Flowers 8-15 mm. broad; petals with several lines of black dots; 

 sepals ovate; leaves oval, 2-8 cm. long, 8-16 mm. wide, conspicu- 

 ously black-dotted; roadsides and open woods. July-Aug. [H. 



pseudo-maculatum Mack. & Bush} H. punctatum Lam. 



1. Stamens few (5-20); flowers small, the petals 3-6 mm. long. 



8. Capsules 3-3.5 mm. long; sepals linear, obtusish; leaves oval, obtuse, 5- 



veined; plants often diffusely branched; moist soil, local. July-Sept 



H. vnitdum L. 



8. Capsules 4-6 mm. long; sepals narrowly lanceolate, acuminate; branching 



strict, erect. 



9. Leaves elliptic-lanceolate, 3-7-veined, acutish at the apex, somewhat 



rounded at the clasping base, 3-10 mm. wide; sepals 5-6 mm. long, 



nearly equalling the capsule; moist ground, rare; n.e. 111., e.xtending 



southwestw. to Peoria Co. July-Aug H. majiis (Gray) Britt. 



9. Leaves linear or linear-oblanceolate, obtusish, 1-3-veined, slightly ta- 

 pered at the sessile base, 1-3 mm. wide; sepals 2.5-3 mm. long, notice- 

 ably shorter than the capsule; moist sandy soil, rare; known from 

 Kankakee and Cook counties. July-Sept H. canadense L. 



3. Sarothra L. — Pineweed 

 1. Leaves scale-like, 2-3 mm. long; capsules much longer than the sepals; 



flowers 4-8 mm. in diameter, nearly sessile; sandy soil, local. Aug. -Oct. 



[Hypericum gentiarioidcs (L.) BSP.} S. gentiaiioides L. 



1. Leaves subulate, 5-20 mm. long; capsules about as long as the sepals; flowers 



10-12 mm. in diameter, pedicelled; sterile soil in the s. half of the state. 



July-Sept. [Hypericum drummondii (Grev. & Hook.) T. & G.} 



S. drumvwndu Grev. & Hook. 



