272 BICKNELL: FERNS AND 
points out to me that its more obvious differences from A. Mille- 
folium are smaller rays, 1.5-2 mm. wide, more delicately dissected 
leaves with narrower unmargined or but slightly margined midrib, 
and more arachnoid pubescence, the crowded heads commonly 
with more cylindric involucres and narrower and paler or more 
stramineous bracts. This yarrow seems to be not uncommon on 
Martha’s Vineyard, where I have collected very typical examples, 
and also on Long Island and near New York. When last on 
Nantucket I did not well enough distinguish it from A. Millefolium 
to learn its real status there, although noting that a yarrow having 
very small rays, now presumably this, was not at all an uncommon 
plant. 
*ACHILLEA PANNONICA Scheele, Linnaea 18: 471. .1835- 
A. lanata Spreng, Cat. Fl. Hal. 1799, not Lam. 1778. 
This yarrow of southeastern Europe, not before, I think, 
reported from America, occurs in scattered growth on the dry 
plains towards the south shore of Nantucket especially neat 
Madequecham Pond. In full flower July 9, 1912. 
A very distinct appearing plant as compared with our common 
forms, densely white woolly throughout and with congested 
rounded or convex corymbs, and small rays 1-1.5 mm. wide. The 
numerous densely lanose-pubescent cauline leaves are narrow and 
ascending or erect, their short segments and subdivisions more OF 
less incurved and closely crowded together. Dr. Rydberg, who 
has determined the identity of my specimens, has called my 
attention to the marked characters by which this plant differs 
from A. lanulosa Nutt. which in some respects it resembles. 
ANTHEMIS COTULA L. 
Mainly in and about the town and suburbs, but also in fields 
and waste places. <A precocious flower June 18, 1910; first flowers 
June 27, 1912; blooming until late autumn. 
CHRYSANTHEMUM LEUCANTHEMUM L. 
Abundant throughout the island, whitening the fields in June. 
Sometimes growing in close groups in pure sand among the beach 
grass. First flowers May 30, 1909; in full flower June 7; 1908. 
All presumably the var. pinnatifidum Lecog & Lamotte. 
