Biology Reference
In-Depth Information
Fig. 9.3
Cleistesiopsis
. (
a
)
C. divaricata
, flower, front view, scale bar = 10 mm; (
b
,
c
) Generalized
figures for
C. divaricata
and
C. bifaria
; (
b
) Column, oblique ventral view with small protrusion on
lower edge of anther cap, scale bar = 10 mm; (
c
) Lip, from above, flattened, showing position of
keel, scale bar = 5 mm.
an
anther,
ro
rostellum,
sg
stigma
granular pollen is considered a secondary reversion (Gregg
1989
; Pridgeon et al.
2003
). The stigmatic area beneath the column is separated from the anther by a
truncate flap of rostellar tissue (Figs.
9.3b
and
9.4b
) (Catling and Gregg
1992
).
Viscidia are absent (Dressler
1993
). Receptive stigmas secrete a sticky, stigmatic
fluid and remain receptive for a minimum of 8 days following anthesis in West
Virginia populations of
C. bifaria
(Gregg
1989
). Unpollinated flowers of this spe-
cies usually remain open and attractive for about 10-12 days.
Compatibility and Breeding System
Gregg (
1989, 1991a, b
) studied the pollination biology of
C. bifaria
at an acidic
mountain meadow site in northeastern Barbour County, West Virginia and
C. bifaria
and
C. divaricata
at Big Island Savanna in Brunswick County, North Carolina,
where flowering specimens of the two species occurred in approximately equal
numbers. Compatibility and breeding system data are available only for the
C. bifaria
population from West Virginia. Autogamy was absent, distant neighbor
crosses (5-30 ft separation) resulted in 93-100% fruit set, and artificial intrafloral
selfing and geitonogamy produced 89-100% fruit set. Average seed weight per cap-
sule was not significantly different among the last three treatments, but intrafloral
Search WWH ::
Custom Search