Subtribe Spiranthinae - The Pollination Biology of North American Orchids: North of Florida and Mexico - page 46

either stunted or failed to emerge, sometimes for 1 or 2 years, usually reappearing,
if at all, as small plants. The availability of stored energy reserves may, therefore,
play a role in limiting the reproductive success of this orchid.
Deiregyne Schlechter
Deiregyne is a genus of about 15-20 species largely confined to the mountains of
Mexico and Guatemala. One species D. confusa Garay (confusing ladies'-tresses)
(Fig. 2.7b ), however, extends into Texas in the Chisos Mountains of Brewster
County. Its flowers produce nectar and a diurnal fragrance, and their size, shape, and
color suggest pollination by bumblebees (Pridgeon et al. 2003 ).
In a study in the state or Durango, Mexico, Luer ( 1975 ) noted bumblebee polli-
nation of a plant identified as S. durangensis Ames and Schweinfurth (= Deiregyne
durangensis (Ames and Schweinfurth) Garay= Schiedeella saltensis Schlechter).
Although Kew's World Checklist of Monocotyledons places this taxon in south
Texas, Garay ( 1982 ), in his study of Spirantheae, referred all specimens of S. duran-
gensis that he examined, including those from Texas, to D. confusa. Brown ( 2002c )
also recognizes this taxon as D. confusa in the Flora of North America. (Although
Garay and Brown are followed here, the World Checklist of Monocotyledons ( 2008 )
recognizes the species as Schiedeella confusa (Garay) Espejo and Lopez-Ferr.) Luer
described the bumblebee as a huge, yellow and black queen that moved slowly
upward in the spicate inflorescence, grasping the lateral sepals and thrusting its head
far down into each flower in search of nectar. In the process, its head contacted the
viscidia, and pollinaria were extracted.
Schiedeella Schlechter
Schiedeella , a genus of nine (Brown 2002b ) to 15 (Pridgeon et al. 2003 ) species is
found from the southern USA to Panama (except Belize) and the Caribbean (Cuba,
Hispaniola). One species, S. arizonica P. M. Brown (red-spot ladies'-tresses), occurs
in the USA from Arizona to Texas (Brown 2002b ). There are no published observa-
tions on the pollination of this orchid. Among related species, Szlachetko ( 1993 )
reported autogamy in S. romeroana Szlach. from Mexico. A rostellum is lacking or
poorly developed in this species, and the pollinia come to lie in direct contact with
the stigma at anthesis. However, the pollinia in Schiedeella are usually attached
dorsally to a well-developed, sheathing, ventral viscidium. Thus, for example,
S. llaveana (Lindl.) Schltr. and S. trilineata (Lindl.) Burns-Bal., from Mexico and
Central America, are xenogamous and thought to be pollinated by foraging bees,
possibly bumblebees, based on the size, color, and odor of the flowers (Pridgeon
et al. 2003 ).