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

892 POACEAE/DICHANTHELIUM
cific taxa at the varietal level (these are not distinguished on the county distribution map). The
following key to varieties is modified from Gould and Clark (1978).
1. Culms definitely hairy; sheaths of culm leaves, at least the lower ones, definitely hairy (pilose to
villous), with ascending to spreading hairs; spikelets 1.2–2.1 mm long __________________ var. acuminatum
1. Culms glabrous or the lower portions slightly hairy; sheaths of culm leaves glabrous or the lowermost
sparsely hairy; spikelets 1.1–1.8 mm long.
2. Spikelets 1.1–1.4 mm long ________________________________________________ var. longiligulatum
2. Spikelets 1.4–1.8 mm long.
3. Panicle narrow, congested, 1/4–1/3 as broad as long, commonly 8–12 cm long _______ var. densiflorum
3. Panicle broad, open, from 2/3 to nearly as broad as long, commonly 5–8 cm long _____ var. lindheimeri
var. acuminatum. WOOLLY ROSETTE GRASS, WOOLLY PANIC. Plant usually pilose to villous. Sandy
open woods; most common in e 1/2 of TX but widespread in the state; s Canada and nearly
throughout the U.S. [D. acuminatum (Sw.) Gould & C.A. Clark var. fasciculatum (Torr.)
Freckmann, D. acuminatum subsp. fasciculatum (Torr.) Freckmann & Lelong, D. acuminatum
var. implicatum (Scribn.) Gould & C.A. Clark, D. acuminatum var. thurowii (Scribn. & J.G. Sm.)
Gould & C.A. Clark, D. lanuginosum (Elliott) Gould, Panicum acuminatum Sw., Panicum
acuminatum var. fasciculatum (Torr.) Lelong, Panicum auburne Ashe, Panicum huachucae Ashe,
Panicum lanuginosum Elliott, Panicum tennesseense Ashe, Panicum thurowii Scribn. & J.G. Sm.]
var. densiflorum (E.L. Rand & Redfield) Gould & C.A. Clark, (densely-flowered), EATON’S RO-
SETTE GRASS. Plant usually glabrous. Moist or wet areas such as bogs and pine savannahs; Houston,
Liberty, and Upshur (BRIT) cos.; Pineywoods, also Gulf Prairies and Marshes; se Canada
and e U.S. w to MI and TX. [D. acuminatum subsp. spretum (Schult.) Freckmann & Lelong,
Panicum nitidum var. densiflorum E.L. Rand & Redfield, Panicum spretum Schultes] According
to Freckmann and Lelong (2003), this taxon resembles D. dichotomum in size and overall habit.
var. lindheimeri (Nash) Gould & C.A. Clark, (for Ferdinand Jakob Lindheimer, 1801–1879, German
born TX botanist), LINDHEIMER’S ROSETTE GRASS, LINDHEIMER’S PANIC. Plant nearly glabrous
or with sparse pubescence. Sandy or rocky ground, in sun or shade; Pineywoods and Gulf Prairies
and Marshes w to West Cross Timbers, also Edwards Plateau; se Canada and e 1/2 of the
U.S., also CA, NM, and OR. [D. lanuginosum (Elliott) Gould var. lindheimeri (Nash) Fernald, D.
lindheimeri (Nash) Gould, Panicum acuminatum Sw. var. lindheimeri (Nash) Lelong, Panicum
lanuginosum (Elliott) Gould var. lindheimeri (Nash) Fernald, Panicum lindheimeri Nash]
Similar to D. dichotomum (Gould 1975b) but differing in having a ligule ca. 1.5–6 mm long (versus
1 mm or less in D. dichotomum).
var. longiligulatum (Nash) Gould & C.A. Clark, (with long ligules), COASTAL PLAIN ROSETTE
GRASS. Similar to var. densiflorum but panicles to 3/4 as broad as long and with smaller spikelets.
Moist or wet areas such as bogs and pine savannahs; Panola Co. (BRIT) in the Pineywoods;
se Canada and widespread in the e U.S. [D. acuminatum subsp. longiligulatum (Nash)
Freckmann & Lelong, D. longiligulatum (Nash) Freckmann, Panicum longiligulatum Nash,
Panicum acuminatum var. longiligulatum (Nash) Lelong] 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 variety to be of conservation concern in TX. �
Dichanthelium boscii (Poir.) Gould & C.A. Clark (for its discoverer, Louis Augustin Guillaume
Bosc, 1759–1828, French naturalist), BOSC’S PANIC GRASS. Plant ca. 40–75 cm tall; culm nodes
densely bearded; leaf sheaths and blades glabrous or with only scattered pubescence; ligule essentially
absent or to ca. 1 mm long; leaf blades 15–26(–40) mm wide; spikelets (3.7–)4–5.2 mm
long. Wooded or low areas; widespread in Pineywoods and w in Red River drainage to Lamar
Co. (Carr 1994); also n Gulf Prairies and Marshes; e U.S. from CT s to FL w to KS and TX. Apr–Jul,
also fall. [Panicum boscii Poir.] The fruits are reportedly dispersed by ants, which are apparently
attracted to a substance (possibly an oil) found under the first glume (Gaddy 1986).