Biology Reference
In-Depth Information
of pollinating insects (Thien
1971
; Thien and Marcks
1972
). Some insects visit all
three species, and it is expedient to consider them together in order to address ques-
tions concerning their interfertility, pollination mechanisms, and reproductive
isolation.
Arethusa bulbosa
L. (Dragon's-Mouth),
Pogonia ophioglossoides
(L.) Ker Gawler (Rose Pogonia), and
Calopogon tuberosus
(L.)
Britton, Sterns, and Poggenburg (Grass-Pink)
Distribution and Habitat
A. bulbosa
is distributed from Manitoba and Minnesota to Newfoundland and
through the Great Lakes to New Jersey with isolated populations in North Carolina
and Saskatchewan (Sheviak and Catling
2002a
).
C. tuberosus
and
P. ophioglos-
soides
overlap
A. bulbosa
in the north, extending further south through Florida to
eastern Texas, again with a few disjunct populations outside this range (Luer
1975
;
Goldman et al.
2002a
; Sheviak and Catling
2002b, c
). The three species are often
found together and may occur in bogs, fens, swamps, wet woods, savannas, mead-
ows, and prairies (Thien and Marcks
1972
; Goldman et al.
2002b
; Sheviak and
Catling
2002a, b, c
). Where sympatric,
P. ophioglossoides
tends to prefer the wetter,
C. tuberosus
and
Arethusa
the drier sites, with
C. tuberosus
exhibiting wider toler-
ances than
Arethusa
(Boland and Scott
1992
). According to Yannetti (in Pridgeon
et al.
2005
),
Arethusa
is short lived and may be more dependent on frequent seed
propagation than the other two taxa.
Floral Morphology
P. ophioglossoides
bears a single terminal or two racemic, resupinate, and gaping
flowers on stems of varying length (Table
8.1
) (Thien and Marcks
1972
; Sheviak
and Catling
2002b
). Flower color is pink to occasionally white, but according to
Heinrich (
1975
) is usually fairly constant. The lip is spatulate with dark red, involute
margins, lacerate and deeply fringed toward the apex (Fig.
8.1a
). Its ventral surface
is ornamented with purple veins and bears three rows of ultraviolet absorbing, yel-
lowish bristles, which become long, red processes toward the apex (Luer
1975
;
Smith
1993
). The column is curved and pink with an incumbent, terminal anther
housing a pair of soft and mealy, ovoid, yellow pollen masses (Fig.
8.1b, c
) (Luer
1975
; Dressler
1993
). True pollinia are absent (Pridgeon et al.
2003
). Pollen is loose
and dispersed in clumps made up of binucleate monads (Gregg
1991
). The stigma is
flat (Sheviak and Catling
2002b
). A viscidium is absent (e.g., Stoutamire
1971
).
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