242 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Stem leaves crenate, dentate, or serrate. 

 Inflorescence and lower surface of leaves covered with fine white down. 



7. S. incana. 

 Inflorescence and lower surface of leaves glabrous or merely pilose. 

 Corolla 12-17 mm. long; leaves somewhat pilose, mostly obtuse. 



8. S. ovalifolia. 

 Corolla 20-25 mm. long; leaves nearly glabrous, acuminate at both ends. 



9. S. serrata. 



1. Scutellaria nervosa Pursh. 



Woods and thickets, probably throughout the region. May-Jime. Eastern N. 

 Amer. 

 A form with entire leaves has been collected. 



2. Scutellaria parvula Michx. 



Woods and sandy banks; apparently not common. May-July. Eastern N. Amer. 

 The rootstock are moniliform and tuber-bearing. 



3. Scutellaria lateriflora L. Mad-dog skullcap. 

 Usually in wet places; chiefly east and south of Washington. July-Sept. Widely 



distributed in N. Amer. 



4. Scutellaria saxatilis Ridd. 



Known only from the rocky wooded banks of the upper Potomac, where it is not 

 rare. 'June-Aug. Del. to Ohio and S. C. 



The thin heart-shaped stem leaves on slender petioles are a marked character. 

 6. Scutellaria ovata Hill. 



Rocky woods; rare; Difficult Run and Great Falls. Jime. Southern states, north to 

 Pa. (S. versicolor Nutt.; S. cordifolia Muhl.) 



6. Scutellaria integrifolia L. 



Common. June-July. Eastern U. S. 



Distinguished by its oblong-lanceolate entire upper stem leaves. 



7. Scutellaria incana Muhl. 



Woods and river banks; collected only at Glen Echo. July-Aug. Eastern N. 

 Amer. (S. canescens Nutt.) 



8. Scutellaria ovalifolia Pers. 



Perhaps our commonest skullcap, particularly above the fall line. May-July. East- 

 ern U. S. (S. pilosa Michx.) 



The rather distant, nearly ovate leaves on nearly simple stems form a ready mark of 

 distinction . • 



9. Scutellaria serrata Andr. 



Fairly common in woods above the fall line. May- June. Eastern U. S. 

 The handsomest labiate of this region; the large blue and white flowers and bright 

 green leaves make a brilliant contrast of colors. 

 S. galericulatn L. is listed in Brereton's Prodromus. 



6. MARRUBIUM L. 

 1. Marrubium vulgare L. Horehound. 



Waste places. June-Aug. Native of Eur. and Asia; widely naturalized in N. 

 Amer. 



7. AGASTACHE Clayt. 



1. Agastache nepetoides (L.) Kuntze. Gla.nt hyssop. 



Woods along the Potomac. July-Sept. Eastern N. Amer. (LopMnthus nepetoides 



Benth.) 



8. NEPETA L. 

 1. Nepeta cataria L. Catnip. 



Fairly common in waflte places. July-Sept. Native of Eur. and Asia; widely 



naturalized in N. Amer. 



