28 BULLETIN 802, U. S. DEPARTMENT OF AGRICULTURE. 
aquatic-vegetation forms and the finely divided debris which con- 
tains seeds, pollen, spores, and chitinous and other fragments may 
be present in varying proportions. Older and more disintegrated lay- 
ers vary in color from dark brown to brownish black and readily 
become granular when weathering. 
The type is derived from a diffuse stage of sedge marsh or wet 
meadow, formed in part by rushes and other grasslike plants which 
are usually present in many peat deposits; they are characterized 
very frequently b}^ the dense clumps or tussocks of Carex striata* 
Semiaquatic plants are abundant in the water-logged depressions 
between the tussocks of sedges, while many herbaceous plants find 
lodgment in such places on the drier ridges and hummocks. 
(b) A subtype which is more characteristic in the transition series 
to the bog group of peat materials consists similarly of a finely 
fibrous feltlike network from rootlets and underground scale-like 
leaves and stem portions of a variety of sedges, but usually includes 
the thickish rootstocks of the buckbean (Menyanthes sp.) and the 
threadlike stems of several bog plants. The material is grayish 
brown to dark brown in color. It is not easily distinguished from 
the peat material formed by sedges which occupy open-marsh 
meadows, except, perhaps, for the occasional resinous and waxy 
components from bog, heath, and other plants and in the fact that the 
lower contact layers are often poorly differentiated from the struc- 
tureless material which formed below the floating sedge mat. Pockets 
of water are not uncommon. 
The plant remains in the bog-sedge subtype show a rather widely 
varying admixture of sphagnum mosses, cranberry (V actinium spp.), 
and other heath plants. Among the sedges Carex filiformis is espe- 
cially active on northern peat-land areas in extending the floating 
marginal platform of a bog meadow. 
The material of poorly disintegrated sedge peat is quite resistant 
to cutting, plowing, and weathering. It is inclined under excessive 
drainage to form a mull, or dust, which is peculiar also to a few other 
types of peat material. 
Various physical and chemical data are given hi Tables I and II, 
among which are the striking differences in ether and alcohol soluble 
extracts. 
BKOWN-MOSS TYPE. 
" Hypnum peat," "Astmoostorf." 
Brownish green to drab-colored, light, spongy, matted material, 
often laminated and porous in appearance, derived mainly from the 
entire plants of various species of Hypnum mosses or related forms 
and containing an interbeclcled admixture, in varying proportions, of 
finely fibrous rootlets from sedges, etc. 
