Jones: Flora of Illinois, 107. Cistaceae 185 



4. Triadenum Raf. — Marsh St. John's-wort 



T. virginicum (L.) Raf. Swamps, local. July-Sept. [^Hypericum virginicum 



L-] 



107. Cistaceae Lindl. — Rockrose Family 



l.Low shrubs; leaves subulate; petals 5, yellow, fugacious; styles slender, elongate 



I. Hudsonia 



1. Herbs; leaves not subulate. 



2. Petals 5, yellow, fugacious; style short; pubescence stellate 2. Helianthemum 



2. Petals 3, greenish or red, persistent; style none; pubescence not stellate 3. Lechea 



1. Hudsonia L. 



H. tomentosa Nutt. Sandy soil, local. Jo Daviess, Lee, and Fulton coun- 

 ties. May-July. 



2. Helianthemum Mill. — Frostweed 



(Crocanlhemum Spach) 



1. Petaliferous flowers 5-12, pale yellow, in a short terminal cymose raceme, 

 their capsules 3-5 mm. in diameter; seeds reticulate; sandy soil in open 



woods, local. June-July. [H. majus sensu Biclcn., non (L.) BSP.] 



H. bicknellii Fern. 



1. Petaliferous flowers solitary (or rarely 2), bright yellow, their capsules 6-9 

 mm. in diameter; seeds papillose; in similar habitats. June. [Lechea major 



L.; Cistus canadensis L.; H. majus (L.) BSP.} 



H. canadense (L.) Michx. 



3. Lechea L. — Pinweed 



1. Stem with spreading (villous) pubescence; leaves of the basal shoots oval; 

 stem leaves oval, 10-25 mm. long, 6-12 mm. wide; sandy soil. July-Aug. 

 L. villosa Ell. 



l.Stem with appressed (strigose) pubescence, or sometim*'^ nearly glabrous. 



2. The narrow outer sepals longer than the inner ones. 



3. Stem 25-70 cm. tall; leaves narrowly elliptical; sandy soil. July-Aug 



L. minor L. 



3. Stems usually 10-20 cm. tall; leaves linear; sandy or sterile soil in 



woods. July-Aug. [L. tenuifolia var. occidentalis Hodgdon] 



L. tenuifolia Michx. 



2. The narrow outer sepals shorter than or equalling the inner ones. 



4. Plants pale green, finely canescent; panicle strict, virgate; sandy soil. 



July-Aug L. stricta Leggett 



4. Plants dark green, more or less pubescent, but not canescent. 



5. Panicle strict, virgate; capsules globose, 2-3 mm. in diameter; sandy 

 soil, rare. July-Aug L. intermedia Leggett 



5. Panicle-branches spreading; capsules ellipsoid, 1-1.5 mm. in diam- 

 eter; sandy soil, n.e. 111.; known from Winnebago, Lake, Cook, 

 Kankakee, and Iroquois counties. July-Aug. £L. moniliformis 

 Bickn.] L. leggettii Britt. & Hollick 



