222 American Midland Naturalist Monogra^'H No. 2 



2. Flowers few, in numerous loose, peduncled, axillary cymes; bracts minute; 

 waste places, occasional; introd. from Eur. \_S. nepeta (L.) Scheele} .... 



C. nepeta (L.) Krze 



1. Plants glabrous; leaves linear, entire, sessile or nearly so; flowers 1-5 in the 

 axils; plants often with short, basal, sterile stolons bearing oval leaves 

 purplish beneath; rocky woods, or sandy ground, local; n.e. 111., extending 

 southw. to Kankakee and La Salle counties. June-Aug. [^Satureia glabra 

 (Nutt.) Fern.] C. glabrum (Nutt.) Ktze 



23. Thymus L. — Thyme 



T. serpyllum L. Roadsides and old fields and gardens, occasional; introd. 

 from Eur. July-Aug. 



24. Pycnanthemum Michx. — Mountain Mint 



{Koellia Moench) 



1 . Leaves ovate to ovate-lanceolate. 



2. Upper leaves whitish; calyx-teeth and bracts pubescent and usually with 

 long bristles; roadsides, fields, and open woods, s. 111., northw. to 



Jackson and Gallatin counties. July-Sept 



-P. pycnanthemoides (Leavenw.) Fern. 



2. Upper leaves not whitish; calyces and bracts canescent; s. 111., northw. to 



Marion Co. Aug.-Sept P. mcantim (L.) Michx. 



L Leaves lanceolate to linear-lanceolate or linear. 



3. Stem glabrous throughout (or rarely with a few minute curved hairs); 



leaves linear; calyx-lobes subulate-lanceolate; dry soil in open woods, 



along roads, and in fields, common. June-Sept 



P. flexuosum (Walt.) BSP. 



3. Stem pubescent. 



4. Stem short-pubescent on the angles; leaves linear-lanceolate, glabrous 



or nearly so; moist ground in woods and along roads. July-Sept 



P. virginianum (L.) Dur. dC Jacks. 



4. Stem copiously short-pilose throughout, or at least above the middle; 

 leaves elliptic-lanceolate, finely pubescent, at least on veins beneath; 



sandy soil along roads and in open woods, common. July-Sept 



P. pilosiim Nutt. 



25. CUNILA L. 

 C. origanoides (L.) Britt. Stone Mint. Wooded ridges, s. III. Aug.-Oct. 



26. Lycopus L. — Water Horehound 



L Calyx-teeth lanceolate, shorter than or equalling the mature nutlets; leaves 

 serrate, not incised; plants stoloniferous. 

 2. Base of plant and stolons lacking tubers; nutlets sharply muricate on top, 



L7-2 mm. long at maturity; wet ground, not infrequent. July-Oct 



L. virginicus L. 



