22. TiLIACEAE 79 



1. Leaves scale-like or subulate. 



16. 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 H. gcntianoides (L.) BSP. 



16. Leaves subulate, 5-20 mm long; capsules about as long as the 

 sepals; flowers 10-12 mm in diameter, pedicelled ; sterile soil 

 in fields or on thinly wooded ridges in the southern half of 



the state. July-Sept 



H. drummondii (Grev. & Hook.) T. & G. 



3. Triadenuni Raf. — Marsh St. John's-wort 

 1. Leaves 2-5 cm long, copiously glandular beneath, sessile or partly 

 clasping at the base, broadest below the middle; swamps or 

 bogs in the northern half of 111. July-Sept. [7". virginicum 



sensu auth., non (L.) Raf.] T. jraseri (Spach) Gleason 



1. Leaves 5-15 cm long, elliptical or oblanceolate, thin. 



2. Leaves sessile, glandless or nearly so; swampy ground in woods; 

 Alexander, Massac, and Pulaski counties. [T. longifolium 



Small] T. tubulosum (Walt.) Gleason 



2. Leaves short-petioled, narrowed at the base, glandular beneath; 

 cypress swamps, and wet ground in woods in southern Illinois. 



July-Aug. [T. petiolatum (Walt.) Britt.] 



T. walteri (Gmel.) Gleason 



20. Elatinaceae Lindl. — Waterwort Family 



1. Plants glabrous: flowers 2- to 4-mcrous; sepals obtuse L Elatine 



1. Plants puberulent; petals, sepals, and stamens 5; sepals acuminate ....2. Bergia 



1. Elatine L. — Waterwort 

 E. hrachysperma A. Gray. Shallow water, rare; Springfield, San- 

 gamon Co., Bebb; Athens, Menard Co., Hall. 



2. Bergia L. 



B. texana (Hook.)Seub. Shores, rare; near Cahokia, Madison Co., 

 H. Eggert in 1874; St. Clair Co., Eggert in 1878. Aug.-Oct. 



21. Sarraceniaceae LaPylie — Pitcher-plant Family 



1. Sarracenia L. — Pitcher-plant 

 S. purpurea L. Peat bogs; Cook, Lake, and McHenry counties. 

 May-June. 



22. Tiliaceae Juss. — Linden Family 



1 . Tilia L. — Linden 

 1. Leaves of the flowering branches glabrous beneath except for tufts 

 of hairs in the axils of the lateral veins, coarsely serrate, abrupt- 

 ly short-acuminate; woods, common. June-July. American 

 Linden. Basswood. \T. glabra Vent.] T. arnericana L. 



