Part 7 - UNC Herbarium

POACEAE 891
Leersia Swartz (Cutgrass)
A genus of about 18 species, tropical and warm temperate. References: Tucker (1988)=Z.
1 Lower panicle branches whorled or closely approximate; spikelets 4.0-5.5 mm long, 1.5-2.0 mm broad; stamens 3 ...............
.................................................................................................................................................................................L. oryzoides
1 Lower panicle branches alternate (rarely opposite); spikelets 2.2-5.0 mm long, 0.8-4.0 mm broad; stamens 2 or 6.
2 Spikelets suborbicular-falcate, 3.0-4.0 mm broad, < 2× as long as broad; principal leaf-blades 10-15 mm wide; stamens
2 ....................................................................................................................................................................L. lenticularis
2 Spikelets narrowly elliptic-falcate, 1.0-2.0 mm broad, > 2× as long as wide; principal leaf-blades usually < 7 mm wide;
stamens 2 or 6.
3 Spikelets 3.8-4.7 mm long, 1.5-2.0 mm broad; panicle branches short, bearing spikelets nearly to their bases;
stamens 6................................................................................................................................................. L. hexandra
3 Spikelets 2.2-3.5 mm long, 0.8-1.2 mm broad; panicle branches long, filiform, the longer ones bearing spikelets
only in their upper half; stamens 2 ........................................................................................................... L. virginica
Leersia hexandra Swartz, Southern Cutgrass. Cp (GA, NC, SC, VA): clay-based Carolina bays, limesink ponds, lakes,
pools, usually in places where periodically or seasonally inundated; uncommon (VA Rare). June-August. Pantropical, ranging
north in North America to MD, TN, and TX. This species is considered a serious weed in the Old World and New World tropics;
in our area, however, it is uncommon and not weedy. [= RAB, C, F, G, GW, HC, K, Z; = Homalocenchrus hexandrus (Swartz)
Kuntze – S]
Leersia lenticularis Michaux, Catchfly Cutgrass. Cp (GA, NC, SC, VA): floodplain forests and swamps; uncommon.
September-October. Se. VA south to n. FL, west to e. TX, north in the interior to IN and MN. [= RAB, C, F, G, GW, HC, K, Z;
= Homalocenchrus lenticularis (Michaux) Kuntze – S]
Leersia oryzoides (Linnaeus) Swartz, Rice Cutgrass. Cp, Pd, Mt (GA, NC, SC, VA): marshes, riverbanks, pond-shores;
common. August-October. Nova Scotia west to British Columbia, south to FL and CA; also in Europe and e. Asia. [= RAB, C,
F, G, GW, HC, K, Z; = Homalocenchrus oryzoides (Linnaeus) Pollich – S]
Leersia virginica Willdenow, White Grass, White Cutgrass. Cp, Pd, Mt (GA, NC, SC, VA): floodplain forests, swamps,
streambanks; common. August-October. Québec west to MN and SD, south to FL and TX. [= RAB, C, G, GW, HC, K, Z; > L.
virginica var. virginica – F; > L. virginica var. ovata (Poiret) Fernald – F; = Homalocenchrus virginicus (Willdenow) Britton –
S]
Leptochloa Palisot de Beauvois (Sprangletop, Feathergrass)
A genus of about 30 species, pantropical and extending into warm temperate areas. The circumscription of Leptochloa has been
controversial; many earlier authors have preferred to separate Diplachne as a separate genus. References: Snow in FNA
(2003a); Snow (1998); Cronquist (1991).
1 Spikelets 1-2.5 mm long, with 2-4 flowers; sheaths sparsely pilose with long, pustular-based hairs .........................................
............................................................................................................................................................L. panicea ssp. brachiata
1 Spikelets 3.5-10 mm long, with 5-12 flowers; sheaths glabrous (rarely slightly scabrous).
2 Lemmas 2-3 mm long, the apex obtuse to truncate, with the midrib often extended as a mucro .................... L. uninervia
2 Lemmas 3-5 mm long, the apex acuminate or awned.
3 Lemmas acuminate; leaf blades 5-10 mm wide .....................................................................................L. panicoides
3 Lemmas awned; leaf blades 1-3 mm wide.
4 Low sprawling grasses, < 5 dm tall; lemma awns (1-) 2.5-5 mm long; first glume 2.5-3.5 mm long; second
glume 4-7 mm long ...............................................................................................L. fascicularis var. maritima
4 Taller grasses, usually 5-10 dm tall; lemma awns 0.5-2.5 mm long; first glume 1.3-3.4 mm long; second
glume 2.2-5 mm long.
5 First glume 2.3-3.4 mm long; second glume 3.4-5.0; lemmas 4-5 mm long, with an awn 0.5-2.5 mm long
.................................................................................................................[L. fascicularis var. acuminata]
5 First glume 1.3-2 mm long; second glume 2.2-3.5; lemmas 3-4 mm long, with an awn 0.5-1 mm long.....
.................................................................................................................. L. fascicularis var. fascicularis
* Leptochloa fascicularis (Lamarck) A. Gray var. fascicularis, Bearded Sprangletop. Pd (NC): bed of artificial
impoundment; rare, adventive from further west. September. Widespread in e. North America, primarily west of the
Appalachians (adventive further east), and extending into South America. [= C, G; < L. fascicularis – RAB, GW, HC, S; < L.
fusca (Linnaeus) Kunth ssp. fascicularis (Lamarck) N. Snow – FNA, K; Diplachne fascicularis (Lamarck) Palisot de Beauvois –
F]
Leptochloa fascicularis (Lamarck) A. Gray var. maritima (Bicknell) Gleason, Salt-meadow Grass. Cp (NC, SC, VA):
fresh to brackish marshes, overwash flats, other disturbed brackish habitats; rare (NC Rare, VA Watch List). August-October.
Along the coast from s. NH south to SC. This taxon appears to warrant status as a species separate from L. fascicularis.