keys to the vascular plants of east texas - Botanical Research ...

HEXALECTRIS/ORCHIDACEAE
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rain. According to Goldman et al. (2002b), plants of this species “examined from the United
States have been self-pollinating because of a reduced rostellum. In central Texas, in particular,
flowers of this species are cleistogamous.” Engel (1987) also noted that often the flowers do not
open. A specimen (Marsden et al. s.n., BRIT; Collins et al. in press) was recently collected at the
Dallas Co. Cedar Ridge Preserve that was nearly lacking in pigmentation—it was very pale
greenish yellow. While the lack of color makes identification to species more difficult, the 11
mm long sepals and lateral petals suggest H. nitida. (RARE 2001, 2002b: G3S3) �m/288
Hexalectris spicata (Walter) Barnhart, (with spikes), SPIKED CRESTED-CORALROOT, CRESTED-
CORALROOT. Plant 15–80 cm tall; stem fleshy pink; racemes with 5–25 flowers; lateral petals yellow-tan
to purplish brown, with brown or purple veins; middle lobe of lip usually yellow to
white or tan, with purple striations; occasionally plants lack purple pigment—the sepals and
lateral petals can then be mahogany brown with darker brown striations, and the lip is all
white except for faint yellowish markings (Luer 1975). The following key to varieties is modified
from Catling and Engel (1993).
1. Flowers usually not opening (typically auto-pollinating, but sometimes opening), the sepals and
petals usually not recurved at tips; the 5 central veins of the lip with their highest keels raised
0.4–0.7 mm above the lip surface; column without a rostellar flap separating the pollen masses
from the stigmatic surface; petals 14–16 mm long, 4–5 mm wide; usually flowering in East TX in
Jun–Jul ________________________________________________________________________ var. arizonica
1. Flowers opening, the sepals and petals often with recurving tips; the 5 central veins of the lip
with their highest keels raised (0.4–)0.7–1 mm above the lip surface; column with a rostellar flap
separating the pollen masses from the stigmatic surface; petals 14–23 mm long, 5–9 mm wide;
usually flowering in East TX in May–early Jun ___________________________________________ var. spicata
var. arizonica (S. Watson) Catling & V.S. Engel, (of Arizona), ARIZONA CRESTED-CORALROOT.
Flowers usually cleistogamous, reduced; rostellum (= structure on column that separates the
anther from the stigma and prevents self-pollination) lacking (Liggio & Liggio 1999); anther
whitish. In rotting wood or leaf litter in oak, pine, or juniper woods over limestone; Anderson,
Dallas, and Travis (Catling & Engel 1993) cos. in East TX; also known from Palo Pinto Co. in the
Cross Timbers and Prairies and Brewster and Culberson cos. in far w TX (Catling & Engel
1993); AZ, NM, and TX. (May–)Jun–Jul, typically later than var. spicata. [Corallorhiza arizonica
S. Watson] Catling and Engel (1993) indicated that most plants seen in the Dallas area and all in
Travis Co. have closed flowers that do not open and are apparently auto-pollinating. They suggested
this taxon is an auto-pollinating race derived from var. spicata; alternatively, they suggested
that var. arizonica might have a hybrid origin, possibly resulting from a cross between
H. nitida and H. spicata var. spicata. The varietal epithet arizonica is taken from the state where
the variety was first collected.
var. spicata, CRESTED-CORALROOT, BRUNETTA, BUFF-CREST, COCK’S-COMB, LEAFLESS ORCHID. Flowers
chasmogamous; rostellum present; anther yellow. Oak, hickory, beech-magnolia, or conifer
(often Juniperus) woods, calcareous sandy or organic soils; widespread in TX except nw and s
parts of the state; according to Catling and Engel (1993), this taxon occurs at the same site (Dallas
Co. Cedar Ridge Preserve) as H. spicata var. arizonica and H. nitida; e U.S. from VA s to FL w to
KS and TX, also AZ and NM. (Apr–)May–early Jun. According to J. Stanford (pers. comm.), these
delicate-appearing plants have massive underground rhizomes (ca. 10 cm in diam.). m/288
Hexalectris warnockii Ames & Correll, (for Barton Holland Warnock, 1911–1998, Trans-Pecos
TX botanist), TEXAS PURPLE-SPIKE, TEXAS CRESTED-CORALROOT. Plant to ca. 30(–40) cm tall; inflorescences
with 3–10 flowers; sepals, petals, and lip ca. (12–)15–20 mm long; lateral petals (12–)
15–20 mm long, maroon or deep purple; lip with middle lobe whitish, edged in purple, with 5
conspicuous yellow crests, 3 of which reach the apex, the lateral lobes of lip pale pink with