naan —— 
BICKNELL: FERNS AND FLOWERING PLANTS OF NANTUCKET 421 
or glaucescent, often whitened beneath, firm and cartilaginous- 
serrulate, the venation prominent, especially on the lower surface, 
glabrous, or puberulent on the midvein on the upper side; corolla 
cylindric-urceolate, about 6 mm. long; calyx lobes commonly 
larger and more venose than those of V. angustifolium; fruit 
glaucous at least when young, becoming dark. 
Type from Nantucket, Tom Never’s swamp, June 13, 1908. 
The Vaccinium pennsylvanicum var. nigrum Wood was de- 
scribed as ‘‘Dark green, berries black and shining without 
bloom” (Bot. and Fl. 199. 1873). The reference is unmis- 
takably to the black-fruited form of V. angustifolium, which is 
not a very uncommon plant and, when in mature fruit, is at sharp 
contrast with the common blue-fruited form with which it grows. 
Vaccinium Brittonti, which is characteristically pale green and 
glaucescent, is altogether a different plant. This was seen long 
ago by the late Doctor Thomas C. Porter, and the name here 
adopted for it was proposed by him in a letter to Doctor Britton 
dated Feb. 25, 1891, now preserved in the herbarium of Columbia 
University. This letter is attached to a sheet bearing two separate 
collections of the plant, one by Doctor Britton from High Point, 
Sussex County, New Jersey, May 30, 1891, the other, by Mr. 
O. A. Farwell, from sand dunes along the shore of Lake Superior 
in Keweenaw County, Michigan, Aug., 1890. There appears to 
be no specimen collected by Doctor Porter or designated by him, 
but his letter is perfectly clear in pointing out the characters that 
distinguish this blueberry from V. angustifolium, which he discusses 
under the then current name of V. pennsylvanicum. On Nan- 
tucket Vaccinium Brittonii was met with only in Tom Never’s 
swamp where it grows in several places in association with 
Cassandra, Gaylussacia dumosa, Aronia nigra, and also Vaccinium 
angustifolium. Last flowers June 13, 1908; green glaucous fruit 
July 2, 1912. 
At the Thousand Islands, in 1905, I found it a representative 
species, particularly on La Rue Island, where it was in fruit late 
in August. The pale green color of the firm oval leaves and the 
white glaucous leafy shoots distinguished it strikingly from V. 
angustifolium and V. canadense, also common there. The mature 
fruit although very dark was covered with a faint glaucous bloom. 
It seems appropriate here to report an evident hybrid between 
