166 THE ORCHID REVIEW. [JuNE, 1922- 
POGONIA AND ITS ALLIES IN THE NORTH-EASTERN 
UNITED STATES. 
NOTHER interesting volume, forming fascicle VII. of Orchidacea, is. 
A devoted to Pogonia and its Allies in the North-eastern United States. 
and other papers by Prof. Oakes Ames, A.M., F.L.S. It contains excellent 
plates, and is issued from the Ames Botanical Laboratory, North-eastern 
Mass., U.S.A. Pogonia when taken in the broad sense consists of a group 
of rather sharply defined subgenera. The present work deals with the 
subgenera of Pogonia that come within the range covered by the seventh 
edition of Gray’s Manual, and by means of detailed plates those characters 
that seem to be most important in considerations of generic segregation of 
the species are made clear. The subgenera of Pogonia include Cleistes, 
Isotria, Triphora, and Psilochilus, all of which are members of that large 
section of the Orchidacez which is characterised by mealy or powdery 
pollen. 
The reasons for raising these subgenera to generic rank may be briefly 
made known by the Summary :—“ The pollinia furnish characters of great 
importance and give three groups of species. Pogonia is first set aside by 
means of simple pollen grains. The remaining groups have the pollen 
cohering in tetrads. Triphora comes out because of the reticulated pollen 
grains and rigidly attached anther, and is sharply differentiated from its: 
allies by means of its vegetative peculiarities and different lip-base. Isotria 
and Cleistes, characterised in part by the unpitted extine of the pollen, 
remain. They are separated from each other by means of the foliage. 
Isotria having five or six leaves disposed in verticils, while in Cleistes the 
leaves are solitary or alternate. The verticils of leaves in Isotria are of 
extraordinary interest, as they indicate a line of development that now lacks 
a parallel in the Orchidacez, the nearest approach to it being found in the 
Antarctic Codonorchis. It is when we consider the significance of 
verticillate leaves in the evolution of the Orchids that this peculiarity in 
Isotria assumes deep significance in attempts at generic segregation.” 
A few words must be said regarding the excellent plates that accompany 
the above article. They are, we believe, the most complete studies, 
pictorially, of Orchid species that were ever attempted, and for fidelity to 
the originals are unsurpassed in the realm of botanical illustrations. F. 
Bauer, the author of “Illustrations of Orchidaceous Plants,” 1830-38, 
never did more careful work than that seen in plates 102 and 103, depicting. 
Triphora trianthophora. The flowers of this species, however, differs from 
other New England Orchids in their brief duration. They fade rapidly 
shortly after the sepals and petals expand, floral perfection evidently being 
a matter of hours rather than of days. But the labellum is a very beautiful 
