Jones: Flora of Illinois, 135. Labiatae 223 



2. Base of rhizome and tips of stolons often bearing a tuber; nutlets smooth 



or merely rugulose on top, 1-1.5 mm. long when mature; moist ground 

 in the n. part of the state, extending southw. to Stark Co. Aug. -Sept. 



L. uniflorus Michx. 



1 . Calyx-teeth subulate, much longer than the nutlets. 



3. Leaves merely coarsely serrate; corolla twice the length of the calyx; wet 



ground, locally throughout 111., except the n. counties. Aug. -Sept 



L. rubellus Moench 



3. Leaves (at least the lower) more or less incised or sinuately pinnatifid; 



corolla slightly longer than the calyx; wet ground, common. July-Sept. 

 [L. siniiatus Ell.} L. americanus Muhl. 



27. Mentha L.— Mint 



1. Whorls of flowers mostly in terminal spikes. 

 2. Leaves sessile. 



3. Stem finely canescent; calyx pubescent; corolla white, about 4 mm. 

 long; roadsides and waste places, occasional; introd. from Eur. Fay- 

 ette Co., Louise Odell in 1940 M. alopecuroides Hull 



3. Stem and calyx glabrous or nearly so; corolla pale pink, 2-2.5 mm. 

 long; moist ground, occasional; introd. from Eur. July-Sept. Spear- 

 mint M. spicata L. 



2. Leaves short-petioled, lanceolate, acute; stem glabrous; calyx-tube gla- 

 brous, the teeth ciliolate; corolla 4 mm. long; waste places and along 

 roads; nat. from Eur. July-Sept. Peppermint M. piperita L. 



1. Whorls of flowers all axillary. 



4. Calyx-tube glabrous, the teeth ciliate; stem sparsely pubescent; leaves oval; 



corolla deep pink, 2.5 mm. long; moist ground, not common; introd. 



from Eur. Aug.-Oct M. gentilis L. 



4. Calyx-tube more or less pubescent. 



5. Leaves ovate, rounded at the base; stem and leaves pubescent; waste 



places, occasional; introd. from Eur. July-Sept. Field Mint 



M. arvensis L. 



5. Leaves lanceolate, cuneate at the base; native species. 



6. Stem villous; leaves pubescent; moist ground, rare. Lake Co., Gleas- 

 07i & Shobe; McHenry Co., Nason. [M. arvensis var. canadensis 



(L.) Briquet] M. canadensis L. 



6. Stem glabrous on the sides, sparsely retrorsely pubescent on the 

 angles; leaves nearly glabrous; moist ground, common throughout 



111. July-Sept. [M. arvensis var. glabrata (Benth.) Fern.} 



M. glabrior (Hook.) Rydb. 



28. COLLINSONIA L. 



C. canadensis L. Richweed. Woods, s. 111., rare. July-Sept. 



29. Perilla L. 



P. frutescens (L.) Britt. Roadsides and waste places, rare; adv. from Asia. 

 Known in 111. from Jackson, Union, Alexander, and Wabash counties. 



