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

ERIOCAULON/ERIOCAULACEAE
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bracts; outer involucral bracts narrowly ovate to lanceolate, 2–4 mm long, acuminate, strawcolored,
with clavate white hairs apically; surface of receptacle villous; receptacular bracts narrowly
acute to acuminate, sometimes visibly exserted; sepals 2–3 mm long, yellowish white,
with clavate white hairs on keel and apex. Meadows, swamps, pond margins, bogs; widespread
in appropriate habitats in the Pineywoods and Post Oak Savannah; also n Gulf Prairies and
Marshes; e U.S. from NY s to FL w to OK and TX. May–Sep. This is the most robust of the East
TX pipeworts. m/286
Eriocaulon koernickianum Van Heurck & Müll. Arg., (for Friedrich August Körnicke, 1828–
1908, German botanist), SMALL-HEAD PIPEWORT, GULF PIPEWORT, DWARF PIPEWORT. Plant annual
or weakly perennial, diminutive, the leaves 1–5 cm long, the mature scapes 5–8 cm long; sheath
of scapes about the length of the leaves; mature heads subglobose or short-oblong, 3–4 mm
broad, dark gray or gray-green except for the pale “rims” of white ciliate perianth parts and
bracts and pale outer bracts; outer involucral bracts broadly oblong to suborbicular, reflexed at
maturity, 1–1.25 mm long, rounded, straw-colored, translucent, not hidden by perianth parts
and receptacular bracts; surface of receptacle glabrous; receptacular bracts acute to obtuse; sepals
ca. 1 mm long, gray-translucent, glabrous or with scattered hairs on the back apically. Upland
seeps, bogs, permanently wet seepage slopes or marsh/bog edges that are not overshadowed
by taller vegetation, often on sphagnum mats, acidic sands to sandy silts, often associated
with sandstone or other rocky outcrops; Anderson, Brazos, Freestone (BRIT), Polk, Tyler (Kral
1966a), Henderson, Limestone (MacRoberts & MacRoberts 1999), and Leon (Carr 2001) cos. in
the s portions of the Post Oak Savannah and Pineywoods (MacRoberts & MacRoberts (1999)
could not confirm the Polk and Tyler county records); also Gillespie Co. (BRIT) at Enchanted
Rock State Natural Area in the e Edwards Plateau; AR, GA, OK, and TX. Spring–early fall. This
rare species was cited by Kral (2000b) as being of conservation concern, has declined in the recent
past, and is a Federal Candidate Species (Watson et al. 1994). Its conservation biology was
discussed by Watson et al. (1994)—a number of factors appear to be contributing to its rareness,
including no vegetative reproduction, low seed set, genetic homogeneity, poor competitive ability,
annual or weak perennial life history, and a restricted habitat. (TOES 1993: V; RARE 2002a:
G2S1SOC) �
Eriocaulon texense Körn., (of Texas), TEXAS PIPEWORT, PIPEWORT. In habit resembling a diminutive
E. compressum (Kral 2000b); leaves 1–5 cm long; mature scapes 5–30 cm long, mature head
usually hemispherical, 5–10 mm broad, gray except for the white hairs of the receptacular
bracts and perianth parts and the straw-colored outer involucral bracts, soft; outer involucral
bracts suborbicular to broadly ovate, ca. 1.5 mm long, rounded to acute, at maturity usually
hidden by the florets (but evident earlier); surface of receptacle with numerous hairs;
receptacular bracts acute; sepals ca. 1.5 mm long, dark gray apically, with clavate white hairs on
keel and sometimes on margins apically. Wet acidic areas, sphagnous bogs (often with Sarracenia—PITCHERPLANT);
widespread in s part of Pineywoods and Post Oak Savannah w to Henderson,
Milam (TAES), Austin, and Freestone (Turner et al. 2003) cos.; se U.S. from NC s to FL w to
TX. Moldenke (1961) indicated Cory recorded the species from the Blackland Prairie. Apr–Jun.
Eriocaulon aquaticum (Hill) Druce, (aquatic), SEVEN-ANGLE PIPEWORT, WHITE-BUTTONS, DUCK-
GRASS, [E. septangulare With.], was reported for TX in vegetational areas 1 and 4 by Hatch et al.
(1990). However, Kral (1979b; 2000b) indicated it occurs in Canada and the n U.S. s only to Alabama;
R. Kral (pers. comm.) confirmed that this species does not occur in TX. According to Kral,
“Early reports of E. aquaticum (E. septangulare) were based on lack of understanding of the
similar-looking E. texense.” Eriocaulon aquaticum can be distinguished by the heads which are
small (4–5 mm wide) and � dark in appearance due to usually gray to almost black
receptacular bracts and perianth parts (only tips of perianth parts and receptacular bracts
have whitish hairs); also the receptacles are glabrous.