1921] Grimes, — A new Station for Pogonia affinis 107 



elongates to about one centimetre. The young ovary is distinctly 

 ribbed, while the ripe capsule is six angled and three ribbed and de- 

 hisces by lateral longitudinal splits on either side of the ribs. At 

 the base of the stem at soil level there are four to five small pointed 

 brown membranous bracts. Time did not permit of prolonged 

 observation and no insect visitors were observed. 



In this station P. affinis is associated with two other orchids, 

 Liparis liliifolia and Microstylis unifolia. The flowering period of 

 the former pretty well coincides with that of the Pogonia, as it was 

 found in flower June 1, 1020, and by May 5, 1021. The flowering 

 period of the Microstylis is slightly later and this plant is found also 

 in pine woods on acid soils. 



There is no possibility of confusing the two species of Pogonia and 

 there are no intergrading forms, they are not even associated in the 

 field. P. verticittata is the larger and more robust orchid, the plant 

 has a reddish tinge 1 and the leaves stand out approximately at right 

 angles to the stem, they are also thicker. Further, the long purplish 

 brown sepals of the Whorled Pogonia are very striking and distinc- 

 tive. 



It is certain that, time permitting a more continued search would 

 have revealed many more plants of this rare orchid in the same area, 

 as those observed all seemed well established and several bore last 

 year's fruiting capsule on a dead shoot. So far no trace of the plant 

 has been found in any other part of this region although the closely 

 related P. verticittata is common here and widely distributed, but it 

 does not occur in the P. ajfuii.s area. P. nrticillaia prefers soils that 

 are medium acid to methyl red, and although it occurs on the borders 

 of flat, dry, pine-oak woods, it does best on the lower edge of wooded 

 slopes bordering the Mood plains of streams, and in this habitat it is 

 often associated with Medeola virgmiana, the young plants of which 

 might at first be mistaken for the orchid. 



College of William and Mary, Williamsburg, Virginia. 



