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

SACCHARUM/POACEAE
1045
1. Awn of lemma of fertile floret spiraled at base with 2–4 spirals, 15–22 mm long; lemma of fertile
floret bifid, with the 2 lateral lobes 2–2.5 mm long ____________________________________ var. contortum
var. brevibarbe. Bowie, Harrison (Webster & Shaw 1995), and Tyler (ASTC) cos.; also n margin of
Gulf Prairies and Marshes; se U.S. from NC w to OK and TX, also MD. This variety is less common
in East TX than var. contortum. [Erianthus brevibarbis Michx.]
var. contortum (Elliott) R.D. Webster, (contorted). Apex of lemma tearing as awn develops spirals
during maturation of spikelet, resulting in the formation of two lateral lobes at apex of
lemma. Widespread in Pineywoods and scattered in n Post Oak Savannah; also n margin of
Gulf Prairies and Marshes; se U.S. from MD s to FL w to OK and TX. [Erianthus contortus Elliott,
Erianthus smallii Nash, S. contortum (Elliott) Nutt.]
Saccharum coarctatum (Fernald) R.D. Webster, (bunched, pressed together), BUNCHED PLUME
GRASS. Plant not or only shortly rhizomatous; culms 1–2.5 m tall, the nodes with hairs 1–3 mm
long; leaf sheaths with auricles 0.3–1 mm long; ligule a fringed membrane 1–2 mm long; leaf
blades 7–12 mm wide, glabrous; callus hairs ca. 1/2 as long as spikelet, 3–5 mm long, white to
straw-colored; spikelets 6–8 mm long; awn of lemma of fertile floret terete at base, not spiraled,
straight or nearly so, usually 16–26 mm long; 2n = 60 (Webster 1994). Open, often seasonally
flooded areas, usually moist sandy soils; Montgomery (TAES), Liberty, and Tyler (Brown &
Marcus 1998) cos.; se U.S. from DE s to FL w to TX. Sep–Oct. [Erianthus coarctatus Fernald,
Erianthus coarctatus var. elliottianus Fernald] This species is similar to S. baldwinii but can be
distinguished by its pubescent nodes, though these sometimes become glabrous at maturity.
The species is also distinguished by the straight, non-spiraled awn of the lemma of fertile floret
and callus hairs ca. 1/2 the spikelet length (Webster & Shaw 1995). Given that it is known from
only three counties in TX, this species is possibly of conservation concern in the state. �
Saccharum giganteum (Walter) Pers., (gigantic), SUGARCANE PLUME GRASS, GIANT PLUME GRASS.
Plant rhizomatous; culms 1–3 m tall, the nodes with a dense ring of hairs 1–6 mm long; leaf
sheaths without auricles; ligule 1–6 mm long; leaf blades (4–)8–20(–30) mm wide, the upper
surface often with hairs; callus hairs longer than spikelet, (7–)15–20(–25) mm long, straw-colored
or brownish, sometimes with purplish tinge; spikelets 4.2–8 mm long; awn of lemma of
fertile floret basally terete, not spiraled, straight or nearly so, 12–26 mm long; 2n = 30, 60, and
90, and thus a polyploid series (Webster 1994). Usually moist sandy soils, but ranging from
standing water to dry hillsides; widespread in East TX w to Henderson, Milam (BRIT), Guadalupe,
and Travis (Turner et al. 2003) cos.; also n Gulf Prairies and Marshes; se U.S. from NJ s to FL
w to MO, OK, and TX, also NY and PA. Sep–Nov. [Erianthus giganteus (Walter) P. Beauv.,
Erianthus giganteus var. compactus (Nash) Fernald, Erianthus laxus Nash, Erianthus
saccharoides Michx.] This species is most similar to S. alopecuroides, and intermediates are occasionally
found (Webster & Shaw 1995). Saccharum giganteum is distinguished by the straight
awn of the lemma of fertile floret and callus hairs longer than the spikelet.
Saccharum officinarum L., (sold in shops, applies to medicinal, edible, and otherwise useful
plants), SUGARCANE, NOBLE-CANE. Plant robust, bunch-forming, rhizomatous; culms to several
m tall, 2–4.5 cm thick, often purplish, solid (the pith with abundant sugar); ligule a membrane
ca. 2–3 mm long; leaf blades to 1+ m long and 4–6(–7) cm wide; inflorescence a plume-like
panicle usually 30–60(–100) cm long; spikelets 3–4(–5) mm long; callus with white hairs longer
than the spikelet; lemma without an awn; 2n = 80 (Webster 2003). Plant cultivated for its high
sugar content; included based on citation of Pineywoods by Hatch et al. (1990) and Hatch (2002);
however, we are unaware of any East TX collections and question whether this species actually
escapes and naturalizes in the area; also Gulf Prairies and Marshes and s South TX Plains; no
county distribution map is provided; FL, LA, and TX. Oct., but rarely flowering (Allen 1992b).
While there is not complete agreement on SUGARCANE’S place of origin, it is probably native either to