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

772 ORCHIDACEAE/PLATANTHERA
Platanthera blephariglottis (Willd.) Lindl. var. conspicua (Nash) Luer, (sp.: tongue like an eyelid
or eyebrow, in reference to the fringed lip; var.: easily seen, conspicuous), LARGE WHITE FRINGED
ORCHID, WHITE FRINGED ORCHID, WHITE FINGER ORCHID, PLUME OF NAVARRE. Plant to 35–110 cm
tall; leaves 2–4, lanceolate, 5–35 cm long, keeled; spikes densely- or loosely-flowered, with 30–50
flowers; flowers white; sepals ovate; petals linear, 3–8 mm long; lip ovate, ca. 1–nearly 2 cm long
(not including fringe), conspicuously fringed marginally, the fringe adding ca. another 1/2 cm
in length; spur slender, 3–4(–5) cm long, as long as ovary or longer. Swamp margins, depressions
in savannahs, hillside seepage bogs, margins of baygalls; included for East TX based on
range map in Luer (1975) showing occurrence in the s part of the Pineywoods; however, a single
Galveston Co. collection to the s of East TX in the Gulf Prairies and Marshes (Correll 1961) is the
only definitive collection known for the state; also known less than 50 miles e of the TX/LA
border in Vernon Parish, LA (MacRoberts & MacRoberts 1995a); se U.S. from NC s to FL w to
TX. Aug–Sep. [Blephariglottis conspicua (Nash) Small, Habenaria blephariglottis (Willd.) Hook.
var. conspicua (Nash) Ames, P. conspicua (Nash) P.M. Br.] Variety conspicua is sometimes recognized
as a distinct species, P. conspicua (Brown 2002b). This taxon is morphologically similar to
the orange-flowered P. ciliaris. Pollination by butterflies and moths has been reported (Luer
1975); Smith and Snow (1976) indicated that P. blephariglottis is pollinated mainly by moths.
Hybrids are known between P. blephariglottis and P. ciliaris, P. clavellata, and P. cristata
(Sheviak 2002b). The northern more widespread var. blephariglottis has smaller flowers with
the spur � 2.6 cm long. While not officially designated as such (e.g., TOES 1993; Carr 2002d;
Poole et al. 2002), given its limited distribution in the state, we consider this species to be of conservation
concern in TX. � m/294
Platanthera chapmanii (Small) Luer, (for A.W. Chapman, 1809–1899, American botanist and author
of Flora of the Southern United States), CHAPMAN’S FRINGED ORCHID, CHAPMAN’S FINGER OR-
CHID, CHAPMAN’S ORCHID. Plant 30–100 cm tall; leaves 1–2(–3), linear-lanceolate, 10–28 cm long,
1–3.5 cm wide; spikes densely-flowered (to 60 or more flowers); flowers orange; sepals suborbicular
to oblong-elliptic; petals narrowly cuneate to oblong-cuneate, 3–4 mm long; lip (not including
fringe) ca. 3–6 mm long, conspicuously fringed marginally; spur slender, (8–)11–14(–17)
mm long. Wet woods, bogs, swamps, especially wetland pine savannahs, acidic soils; in the s
part of the Pineywoods in Hardin, Jefferson (Correll 1961), Orange, and Tyler (Liggio & Liggio
1999) cos.; FL, GA, and TX. While once abundant in parts of the Big Thicket, habitat conversion
for pine-plantations and residential development has destroyed most of this orchid’s habitat
(Liggio & Liggio 1999). Jul–Aug. [Blephariglottis chapmanii Small, Habenaria �chapmanii
(Small) Ames] This species is intermediate morphologically between P. ciliaris and P. cristata
and has been considered by some to be a hybrid between these two species (Luer 1975). However,
Folsom (1984, 1995) concluded that P. chapmanii is a distinct species, and Brown (2002a)
noted that while it may have originated as a hybrid, it is a “stable, reproducing species.” Most
populations of these three “yellow-fringed orchids” are morphologically “pure,” P. chapmanii
grows true from seed, and in the area where P. chapmanii is most common (near Apalachicola,
FL), P. ciliaris is absent (Folsom 1984). Brown (2004a) recently clarified the situation by emphasizing
that P. chapmanii is a species with an ancestral hybrid origin, while �channellii Folsom
is a morphologically similar current hybrid with the same parentage (P. ciliaris � P. cristata ).
Pollination is by long-tongued butterflies as in P. ciliaris; however, the shorter spur of P.
chapmanii results in the pollinia being attached to the butterfly’s proboscis—rather than to the
eyes as in the case of P. ciliaris. This pollination difference apparently acts as a reproductive isolating
mechanism (Folsom 1984). Joe Liggio (pers. comm.) noted that this species is rare and geographically
restricted to n FL, s GA, and East TX. Brown (2002a) indicated that more than 90
percent of all the known plants are in FL. Thus, even though not officially recognized as such
(TOES 1993; Carr 2002d; Poole et al. 2002), because of its decreased abundance and limited occurrence
we consider this species to be of conservation concern in TX. � m/294