Botrychium simplex E. Hitchcock (little grapefern) - Colorado Natural ...

Figure 3. Botrychium simplex var. compositum (“western” simplex) collected on Boreas Pass, Colorado.
The gametophytes of Botrychium species remain
poorly understood. They are achlorophyllous and
are wholly dependent on mycorrhizal fungi for their
water, mineral nutrients, and carbohydrates (Campbell
1922, Bower 1926, Scagel et al. 1966, Gifford and
Foster 1989, Schmid and Oberwinkler 1994). The
gametophytes of other Botrychium species have been
cultured and studied (Campbell 1911, Whittier 1972,
Whittier 1973, Whittier 1981, Whittier 1984, Melan
and Whittier 1989, Thomas and Whittier 1993).
The gametophyte of Botrychium simplex was
studied in detail by Campbell (1922). Like all other
Botrychium species studied, the gametophyte of B.
simplex has a dorsal ridge that bears the gameteproducing
structures. Antheridia are borne at the top
of the dorsal ridge and archegonia on either side of
the dorsal ridge. The gametophytes of B. simplex
are monoecious, with both male and female gameteproducing
structures. The gametophyte is up to 5
mm long and is usually obovoid or club-shaped. The
rhizoids (root-like structures) form on the lower surface.
Botrychium simplex gametophytes have been found
with young sporophytes attached (Clausen 1938).
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Sources for keys photographs, illustrations, and
descriptions
There are numerous sources of keys, photographs,
illustrations, and descriptions that are of great value in
identification of Botrychium simplex. The best source
currently available for use in Region 2 is Farrar (2005),
which includes keys, descriptions, photographs, and a
discussion of the diagnosis, distribution, and habitats
of all western North American moonworts. This source
includes details for each of the currently recognized
varieties of B. simplex (vars. simplex, tenebrosum,
compositum, and fontanum), but unfortunately it is
unpublished and is not yet widely available. Root
(2003) is another useful but unpublished source of
information on moonworts in Colorado that includes
keys, silhouettes, and diagnostic information. Wagner
and Wagner (1993) include a description of B. simplex.
Lellinger (1985) includes a good description, key,
and photograph. Internet sources including Wisconsin
State Herbarium (2003) and Rook (2002) contain
photographs, habitat information, and links to other
sources. Wagner and Wagner (1983) include a figure
showing the varieties of B. simplex.