208 Rhodora [SEPTEMBER 
In dehiscence the valves of the sporangia open very widely and recurve 
so that the open sporangium is nearly flat with a depressed pit in the 
center at the point of attachment. When moist, the empty sporangia 
close again, and are then of a distinctly flattened or lenticular form 
(see fig. 6, A and B). The walls of the sporangia are nearly opaque 
as seen under a microscope, and the superficial layer of the wall 
is seen to consist of irregular cells with thick, sinuous walls (see 
fig. 6, C). 
Typical Botrychium virginianum is a plant found usually in rich 
deciduous woods. It is most abundant in calcareous regions, and - 
ranges from Prince Edward Island to Minnesota, and south to Florida 
and Texas,! reappearing in exactly the same form in eastern Asia. 
Fig. 6. A-C, Botrychium virginianum (L.) Sw. D-F, B. virginianum var. laurentianum 
Butters. A and D, group of sporangia, dehisced, but moist, dorsal view, X 5. B and E, dry, 
dehisced sporangium, ventral view, X 10. C and F, group of cells from the sporangial wall, 
X 75. 
In the Gray Herbarium there are two specimens of it from the latter 
region, one collected by Dr. August Henry (no. 5799) in the province 
of Hupeh, China, the other by K. Watanabe in the province of Tosa, 
Japan.” 
The plant found about the Gulf of St. Lawrence is a hitherto unde- 
scribed variety, BOTRYCHIUM VIRGINIANUM (L.) Sw. var. lauren- 
1 As has been recently pointed out by Ivar Tidestrom (Botrychium virginianum and its forms. 
Contrib.. U. S. Nat. Herb. xvi. 299. 1913.) Botrychium gracile Pursh (Flora Am. Sept. 656. 
1814), described originally from Virginia, is only a young stage of the typical Botrychium 
virginianum. 
2 In Japan occurs also the closely related Botrychium strictum Undw., Bull. Tor. Bot. Club, 
xxx. 52 (1903), of which there is in the Gray Herbarium a single specimen collected by Maxi- 
mowiczin Yokahama in 1862, This is quite distinct from any North American form known 
to the author. 
