179 
seem to have some connection with the fertilization of the pistil. 
I should like to know whether any other species of Opuntia, or, indeed, 
of any of the Cactaceae, have a like sensibility. 
I found this afternoon a twig of Solidago lanceolata, L., which 
presents the decéded peculiarity (to me) of being decidedly glaucous. 
It grew with large quantities of the common §S. lanceolata and S. 
tenuifolia along the salt meadows near New Dorp. [The leaves are 
beset with resin-like spots, not truly glaucous, nor, as Mr. Peck in- 
forms us, due to fungoidal growth.—Eps. } N. L. Brirron. 
New Dorp, Sept. 17th. 
§ 190. Gentiana Andrewsii, Griseb.—It is curious to see a flower 
with so conspicuous and high-colored corolla as that of Gentiana 
Andrewsii ranked as probably cleistogamous. Here the corolla opens, 
like other Gentians, in bright sunshine, although only for a short time. 
Here, too, humble bees are seen to force their way into the closed 
flowers in the manner described by W. W. Bailey. The flowers last 
for a rather long while; the extrorse anthers open and expose the 
pollen long before the stigmas are ready ; when these become exserted 
by the further growth of the ovary, they at first separate moderately, 
exposing the receptive surface to an entering bee, but not to the 
pollen below: at length they diverge widely, become revolute, and 
rh) / in doing so they bet“ rarely bring the stigmatic surface into direct 
contact with the pollen below,—thus securing self-fertilization when it 
may no better be. This is the upshot of my observations a year ago 
in the Botanic Garden here. A. GRay. 
CAMBRIDGE, Oct. 15th. ro 
§ 191. Pollen of different sizes.—In noting the unequal size of 
the pollen grains of the trimorphic flowers of Pontederia cordata, I 
had forgotten that Darwin had, in 1864, pointed out the difference 
in color and size of pollen grains of the different kinds of stamens in 
Lythrum. The statement, therefore, that Pontederia was perhaps 
even more curiously trimorphic than Lythrum, was hasty. In fact, 
as Dr. Koehler points out to me, dimorphic as well as trimorphic 
flowers are known to bear pollen grains varying in size to suit the 
adaptations of the flowers. WwW. be 
§ rg2. Viola cucullata.—Explanation of the economy of the 
cleistogamous flowers of this plant in the last BULLETIN were read 
on occasion of the exhibition at the Club of very fine specimens. 
As printed, without this statement, they seem to be offered asa 
novelty, to which, of course, they have no claim. 
§ 193. Alpine Plants.—Mr. C. G. Pringle, of Charlotte, Vt., 
offers for exchange or sale a few sets of the Alpine Plants of New 
England, the fruit of his extensive herborizing during the past sum- 
mer in the White and Green Mountains. Mr. Pringle’s collections 
contain Gentiana Amarella var. acuta (American Naturalist, Vol. I1., 
page 620), Amemone multifida, Astragalus Robbinsit, Gnaphalium 
supinum, Orchis rotundifolia, Danthonia compressa, and all, or nearly 
all, the other rare plants of his region. a 
§ 194. Florida Plants.—Miss M. C. Reynolds, St. Augustine, 
Fla., has sets of plants for sale. Mr. Le Roy, Columbia College, 
'N. Y., has some of these on hand. gs ) 
