310 MENTHACEAE. 



2. V. prostrata R. Br. Soft-villous to hirsute, diffusely spread- 

 ing, at length much branched, 5-9 dm. long; leaves obovate or 

 oblong, with cuneate base tapering into a margined petiole, veiny, 

 acutely incised and serrate, often 3-5-clcft; spikes solitary or some- 

 what clustered, elongated, hirsute or villous; bracts subulate, 

 shorter than the calyx; corolla violet or blue, 4 mm. long; nutlets 

 oblong. 



Common on the plains and in the foothills throughout our range. 



3. V. bracteosa Michx. Hirsute, much branched from the 

 base, the branches diffuse or decumbent, 2-4 dm. long; leaves 

 cuneate-obovate, narrowed into a short-winged petiole, pinnately 

 incised or 3-cleft and coarsely dentate; spikes thick, terminating the 

 branches; lowest bracts often pinnatifid or incised, the others lance- 

 olate, acuminate, entire, rigid, all exceeding the flowers; corolla 

 purplish or blue. 



Occasional in low ground, especially in the bottoms of dried up 

 ponds. June-September. 



2. LIPPIA L. 



Perennial herbs with opposite sometimes verticillate 

 or rarely alternate leaves, and small bracted flowers in 

 axillary or terminal heads or spikes. Calyx small, mem- 

 branous, ovoid, campanulate or compressed and 2- 

 winged, 2-4- toothed or 2-4-cleft. Corolla cylindric, the 

 limb oblique, spreading, somewhat 2-lipped, 4-cleft, the 

 lobes broad, often retuse or eroded. Stamens 4, didy- 

 namous; anthers not appendaged, the sacs nearly parallel. 

 Ovary 2-celled; ovules 1 in each cell; style short; stigma 

 oblique or recurved. Fruit dry with a membranous 

 exocarp, at length separating into 2 nutlets. 



1. L. lanceolata Michx. Green, glabrous or very sparingly 

 pubescent with forked hairs; stems slender, weak, procumbent or 

 ascending, often rooting at the nodes, simple or little branched, 

 3-6 dm, long; leaves thin, oblong, ovate or ovate-lanceolate, short- 

 petioled, acute, sharply serrate to below the middle, narrowed at 

 base, 2.5-7 cm. long; peduncles axillary, slender, usually longer 

 than the leaves; heads at first globose, becoming cylindric, about 

 15 mm. long in fruit; bracts acute; calyx flattened, 2-cleft; corolla 

 pale blue, scarcely longer than the calyx. 



Occasional along slow-running streams in marshy places. June- 

 August. 



Family 92. MENTHACEAE. Mint Family. 



Aromatic punctate herbs or shrubs, with mostly 4- 

 sided stems, simple opposite exstipulate leaves, and irre- 

 gular perfect flowers variously clustered. Calyx regular 



