134 Rhodora [AvGusT 
Potyconum minus Huds. Fl. Angl. 148 (1762). This delicate 
species, closely related to P. laxiflorum above discussed, is not gener- 
ally recognized as a North American plant but in the Gray Herbarium 
are two sheets from Lancaster County, Pennsylvania, which are 
clearly referable to it. The first collection was made on October 31, 
1891, by Heller & Small in Smithville Swamp No. 2 and distributed by 
Heller as no. 652, P. acre HBK. The other collection was made by 
Mr. Heller on September 23, 1901, in a swamp two miles south of 
Refton and distributed as P. punctatum, var. leptostachyum (Meisner) 
Small. P. minus is a very slender species with glabrous perianths and 
lustrous achenes, much as in P. laxiflorum but very much smaller, 
the achenes only 1.5 mm. long, those of P. laxiflorum being 3 mm. long. 
The Lancaster County material exactly matches the plate in the 
Moss’s Cambridge British Flora designated P. minus, var. subconti- 
guum, which is there ascribed to Wallich, PI. Asiat. Rar. iii. 57 (1832). 
But Wallich neither published the plant under P. minus nor as var. 
subcontiguum, and in fact the treatment in Wallich’s work was by 
Meisner. The variety was published as P. strictum All., var. sub- 
continuum. As a variety of P. minus it should be called 
Potyconum MINUS Huds., var. subcontinuum (Meisn.), n. comb. 
P. strictum, var. subcontinuum Meisn. in Wallich, PI. Asiat. Rar. iii. 
57 (1832). P. mite * strictum, b. pusillum Fries, Fl. Suec. Mant. ii, 32 
(1839). P. minus, var. subcontiguum Rouy, Fl. Fr. xii. 102 (1910.)— 
In this variety the spikes are very straight (not curving or drooping) 
and closely flowered, ranging in length from 1-2 cm. 
POLYGONUM SAGITTATUM L., forma chloranthum, n. f.— perianthiis 
viridibus. 
Perianths green.— Marne: tidal mud-flats of Cathance River, 
Bowdoinham, September 14 & 19, 1916, Fernald & Long, no. 13,559 
(TYPE in Gray Herb.). 
Throughout its range both in America and in Asia P. sagittatum 
normally has the flowers pink,— either deep rose-color or pale pink — 
or sometimes nearly white, but on the tidal flats of Cathance River 
the green-flowered form is very abundant and so uniform as to give 
a distinctive color to large areas of the flats. The plant is there so 
constantly green-flowered that it deserves at least formal recognition. 
The material gathered on September 19 was still in young flowering 
condition and in only a few heads are the achenes well formed. It is 
possible that the plant growing in this estuary, subject to regular 
