remaining pigments, for example, yellow or green. In such 
cases, the word "albino" can be misleading. It also fails to 
indicate which pigment is missing and whether the flower or the 
rest of the plant is affected. 
A striking example of the absence of an anthocyanin is the 
white-flowered form of the Pink Lady's Slipper (Cypripedium 
acaule forma albiflorum ) with its pure white lip (Figure 3). 
The sepals, which are usually reddish-brown because of the 
presence of both the magenta anthocyanin and green chlorophyll, 
are now green. The critical diagnostic feature of this form is 
the pure whiteness of the lip. Occasional plants, as well as 
the buds, can be quite pale, but these are not forma albiflorum. 
Sometimes several white-lipped plants occur fairly close to each 
other as a small group in a much larger stand of the normal 
form. White-flowered plants then recur from year to year in 
this same group. Probably the same plants are producing these 
white flowers each year, but we have not marked individual 
plants to prove this point. 
In the District, this form was first collected in 1906 near 
Aylmer, Quebec, by W.H. Harrington. Five more stands have been 
recorded in recent years. Bill Dore (1969) reported a stand in 
the Larose Forest. Unfortunately, this large colony has been 
much reduced in numbers, probably due to the growth of the 
forest and undergrowth. West of the Rideau River in Ottawa- 
Carleton, three other colonies are known. For years, Enid and 
Clarie Frankton have visited a colony in the western Greenbelt 
close to Highway 417. Harry Thomson photographed a colony in 
March Township in 1968, and that same year, members of the 
Club's Native Orchid Location Survey discovered another colony 
in Huntley Ward of West Carleton Township. From north of the 
Ottawa River, Daniel Gagnon reported 12 plants in the western 
part of Gatineau Park to the Native Orchid Location Survey in 
1975. 
There is also a pure white form of the Small Purple 
Fringed-orchid (P. psycodes forma albiflora). Again, some pale 
individuals also occur, but a close examination of these plants 
will reveal the remaining lilac pigment of the outer part of the 
lip in contrast to the natural pure white at the base of the 
lip. (Petrie's photograph of Platanthera grandiflora mentioned 
above illustrates this subtlety.) In forma albiflora, the en¬ 
tire lip is a uniform pure white. The first record of this form 
in the District seems to be a report of a collection by Henry 
Ami from Ironside in 1888 (Fletcher, Small and Baptie 1888). Ed 
Greenwood told us in 1977 about two plants of this form that he 
found near Buckingham in 1962, describing their flowers as "very 
pure, dazzling white and very beautiful". However, in recent 
years, the area in question was so heavily overgrown that no 
plants could be found. More recently, in 1980, we encountered a 
few plants among a colony of about 35 normal plants discovered 
by Ross Layberry near the Mountain Road south of Gatineau Park 
74 
