Word Study
sphagnum
CIDE DICTIONARY
sphagnum, n. [NL., fr/ Gr. a kind of moss.].
A genus of mosses having white leaves slightly tinged with red or green and found growing in marshy places; bog moss; peat moss. [1913 Webster]
OXFORD DICTIONARY
sphagnum, n. (pl. sphagna) (in full sphagnum moss) any moss of the genus Sphagnum, growing in bogs and peat, and used as packing esp. for plants, as fertilizer, etc.
Etymology
mod.L f. Gk sphagnos a moss
For further exploring for "sphagnum" in Webster Dictionary Online