458 BICKNELL: FERNS AND FLOWERING PLANTS OF NANTUCKET 
June 2, 1910. Farther east, in a more protected thicket beyond 
Abram’s Point, it reaches a height of ten feet and seems to bloom 
a few days later; isolated groups occur also in thickets in Quaise, 
in Shawkemo, at Pocomo Head Pond, where it was passing out 
of bloom June 12, 1909, and at several localities in Squam. A 
small colony was also discovered on Tuckernuck, on a visit made 
to that island on June 17, 1911. Flowers spreading 1.75-2 cm.; 
the petals sometimes tinged with pink; leaves thinner than in any 
other of the Nantucket species, the thorns longer and more 
slender. Well developed green fruit was collected June 26, 1910. 
A tree growing at the border of Dyleave Swamp was perhaps the 
largest native thorn tree seen on the island, having’a height of 
perhaps fourteen feet and a spread of six paces. 
Specimens from several of the stations show rather well marked 
differences and may represent more than one species. Mr. Eggles- 
ton considers it unsafe to express an opinion on this point until 
mature fruit is collected. Specimems from the Abram’s Point 
station differ from all the others in having slightly pubescent to 
loosely villous corymbs. . 
There is also a form of Crataegus on Nantucket that I have 
collected at three stations, in Shawkemo, Wauwinet, and Squam, 
which is almost certainly distinct from Crataegus pruinosa, having 
more deeply and acutely lobed leaves of firmer texture, stouter 
thorns, and rather larger flowers, the number of stamens some- 
times less than twenty and even reduced to ten or twelve. All 
of these are characters that would be derivable from Crataegus 
Bicknellii, and it would seem to be quite possible that this ambigu- 
ous thorn is a hybrid of that species and Crataegus pruinosa. I 
do not myself, however, dare venture into the taxonomy of our 
wild thorns, and up to the moment of going to press have had no 
opportunity of submitting this case to the expert judgment of 
Mr. Eggleston. 
*CRATAEGUS MACROSPERMA Ashe. 
A group of about thirty small trees in a low thicket in Squam, 
forming a sort of miniature contracted grove, perhaps twelve to 
fifteen yards in longer extent. The trunks of the larger of these 
trees are straight and erect and mostly unbranched below, or 
with the branches ascending, so that it is possible to walk about 
