216 American Midland Naturalist Monograph No. 2 



var. leiocarpa Perry & Fern ] Said to hybridize with V. bracteata, V. 



hastata, and V. stricta. White Vervain V. urticaejolia L. 



3. Corolla blue; spikes slender; fruiting calyx more than 2 mm. long. 

 4. Plants densely soft-pubescent; leaves oval or ovate, serrate; calyx 4-5 

 mm. long; nutlets ellipsoid, 2.5 mm. long; roadsides and fields, 



common. June-Sept. Hoary Vervain V. stricta Vent. 



4. Plants glabrous, or sparsely rough-pubescent. 



5. Leaves lanceolate, acuminate, petiolate, the petioles 1-2 cm. long; 

 calyx 2-3 mm. long; nutlets smooth, 1.5-2 mm. long; roadsides 



and open woods, common. July-Sept. Blue Vervain 



V. hastata L. 



5. Leaves linear to oblanceolate, obtuse, sessile or nearly so; calyx 

 3-4 mm. long; nutlets reticulate, 3 mm. long; roadsides and 

 fields. June- Aug. \V . angustifolia Michx.} Said to hybridize 

 with V. stricta, V. hastata, and V. bracteata. Narrow-leaved 

 Vervain V. simplex Lehm. 



2. Phyla Lour. — Frog-fruit 



{Lippia Houst.) 



P. lanceolata (Michx.) Greene. River banks, shores, along ditches, and in 

 wet meadows, common. June-Sept. 



135. Labiatae B. Juss. — Mint Family 

 (Menthaceae L. F. Ward) 



1. Corolla nearly regular, almost equally 5- (or 4-) lobed. 

 2. Leaves entire or essentially so; plants glandular-puberulent. 



3. Stamens included or only slightly exserted; calyx nearly equally 5-toothed 



2. Isanihus 



3. Stamens long-exserted and strongly upcurved; calyx with 3 long and 2 short teeth 



3. Trichosiema 



2. Leaves serrate, crenate, or pinnatifid. 



4. Fertile stamens 2; plants inodorous 26. Lvcopiis 



4. Fertile stamens 4; plants strongly aromatic 27. Mentha 



I. Corolla very irregular. 



5. Calyx with a small crest or callosity on the upper side, 2-lipped: stamens 4 



4. Sciilellaria 



5. Calyx not crested. 



6. Flowers in compact axillary whorls, or in terminal heads or capitate clusters. 

 7. Bracts broad, conspicuous; corolla 2-3.5 cm. long; flowers in dense head-like 



clusters; calyx tubular, equally 5-toothed, I5-nerved; stamens 2 



18. Monarda 



7. Bracts smaller; corolla shorter. 



8. Stem corymbosely branched, stiffly erect; flower-heads clustered; leaves 

 linear, lanceolate, or ovate; calyx nearly regular, 5-toothed, IO-13-nerved 



24. Pxicnanibemitm 



8. Stem simple or with few branches. 



9. Calyx with 10 recurved teeth; corolla white, 5-6 mm. long; leaves ovate, 



petioled, crenate, rugose; stem canescent 5. Marruhiiitn 



9. Calyx with fewer than 10 teeth. 



10. Stamens strongly exserted beyond the corolla; flowers in dense terminal 

 heads or spikes 6. Agastache 



