The fruit-heads are rather larger and more densely fruited than in Canadense and usually paler green, and the mature achcnes are slightly larger with longer slenderer beak. The re ceptacle is also longer and more cylindric, with coarser and stiffer tawny in Canadense it is ovoid and clothed with longer and weaker white hair.
Goan flavrtm needs no close comparison with the very distinct G. although according :to our text-books its flowers would refer it to the latter rather than to Canadense, and this very mistake appears to have been made in some of our local lists. It may be noted, therefore, that the flowers of Viiginianum arc con siderably larger, especially the central carpellary portion ; the creamy-white petals arc larger, 2"-3" long, I y,"-2" wide and ob ovate-oblong, with revolute margins, thus often appearing linear. The pubescence of the stem in is bristly-hairy throughout. In bothflazntm and Canadensc the pubescence above is very fine and close, in the former often with longer scattered hairs.
Gemn fiavum comes into flower at New York from the cnd of June to the middle of July, one to three weeks later than G. Cana
dense, which begins to bloom, according to the season, from the second to the fourth week of June. G. Firginianum flowers still earlier, usually in the first week of June.
The latter is distinctively a plant of boggy ground. G. Caruzdense is the most generally scattered of the three species, oc curring in damp or dry soil in woods and thickets and along road sides. G.flarum is more solitary in its habits, and grows chiefly in rich, loose soil, in copses or upland woods, often among rocks.
The range of G. flavunt appears to be much more restricted than that of Canadense. Prof. Porter has found it common at Easton, Pa., the type locality, and it is also common at New York. Elsewhere it seems to have been detected only in Lancaster county, Pa., and at Marion, Va., at an altitude of 2100 feet, by Dr. Small.
It is interesting to note that this species was known to Muhlen berg, who took it up in his Catalogue' as G. Firginianum L., naming the latter plant G. Ini-sutuni, and distinguishing the two species by their different times of flowering.