Steele Additions to the Flora of Washington. si 



reduced in length to mere cusps; and finally, that the pappus is of a 

 purple brown color, fading grayish. 

 388a. Vernonia glauca (L.) Britton. 

 Xerratitl-a glauca L. 



Vernonia Noveboracemis latifolia A. Gray. 

 Vernonia Noceboracensis tomentosa Britton. Not Chrysccoma 

 tomentom Walt., nor Vernonia tomentosa Ell. 



Mostly on hills; Linnaean Hill road, Rock Creek Park, Glen Echo 

 Heights, and various points on the Virginia side of the Potomac. Also 

 at Harper's Ferry, particularly on Maryland Heights, at an altitude of 

 1,000 feet. I have given much outdoor attention to this plant, and as it 

 does not seem to be well understood, I subjoin a revised description: 



Stem slender to medium stout, strict nearly or quite to the inflores 

 cence, striate-angled, puberulent. Leaves light green above, pale and 

 puberulent or glabrate beneath, the larger from 5 to 7 inches long, and 

 from 1^ to nearly 3 inches wide, the upper portion oblong or oval, acu 

 minate or at least acute, below more or less abruptly incurved-contracted 

 into a margined petiole tapering nearly or quite to the insertion, the 

 narrow portion of variable length; the upper leaves smaller and more 

 nearly cuneate at the base: inflorescence spreading and rather flat-topped, 

 the branches stout, zigzag, dense'ly puberulent, sometimes a lijtle tomen- 

 tose: involucre about H lines broad, the scales cuspidate, subulate- 

 acuminate, or short-awned, the exposed portion purple throughout, or 

 green with purple edges and tips, webby-ciliate, the aw r n, when present, 

 often more or less upwardly barbellate: pappus straw-colored, from 

 nearly white to a rather bright yellow: achenes from one-fourth to one- 

 fifth as thick as long. 



The diagnosis in the Hortus Elthamensis of Dillenius, upon which the 

 Linnaean 'Serratnia glauca was based, alludes to the light-colored pappus, 

 but recent authorities have taken no account of this conspicuous and 

 substantial character, nor do they seem to have attached any importance 

 to the peculiar contraction of the lower part of the leaf, nor to have 

 laid any stress upon the difference, in comparison with Noreboracen*)*, 

 in the habit and inflorescence. As to the involucral scales, the copious 

 material examined shows that they are commonly either abruptly 

 contracted into a short or long cusp, or gradually narrowed to a 

 subulate point with no fast line between the two types, the cuspidate 

 form being, however, the more common. This account, moreover, is 

 sustained historically: for the figure in the Hortus Klthamensis repre 

 sents the bracts, not. indeed, as awned, but as subulate-acuminate, and 

 Dr. Gray states that "the [Linnaean] specimen has many aristate- 

 tipped bracts". To accept Dr. Britton's description of the bracts as 

 "acute or mucronate" would be to throw out a large part, if not allot' 

 the material I have seen, and indeed to leave much of it without a name; 

 for aside from the fact that it is not Noceboracemis at all, a large portion 

 would be excluded from the variety tonn>n1o*a Brit ton by the characters, 

 "leaves densely puberulent beneath" and "involucre purple", as 'the 

 pubescence is not generally very dense, and the involucre is not seldom 



