Plants annual or perennial; cespitose, rhizomatous, or stoloniferous. Culms 3-400 cm, erect, spreading or prostrate, sometimes trailing for 200+ cm. Sheaths open; auricles sometimes present; ligules membranous. Inflorescences terminal, sometimes also axillary, panicles of 1-many spikelike branches, these digitate or racemose on the rachis, spreading to erect, 1 or more branches completely or partially hidden in the sheaths in some species; branch axes flattened, usually narrowly to broadly winged, usually terminating in a spikelet, sometimes extending beyond the distal spikelet but never forming a distinct bristle; disarticulation below the glumes. Spikelets subsessile to shortly pedicellate, plano-convex, rounded to acuminate, dorsally compressed, not subtended by bristles or a ringlike callus, solitary or paired (1 spikelet of the pair reduced in some species), in 2 rows along 1 side of the branches, with 2 florets, first rachilla segment not swollen, upper glumes and upper lemmas adjacent to the branch axes; lower florets sterile; upper florets sessile or stipitate, bisexual, acute or rounded. Lower glumes absent or present only on some spikelets of each branch, without veins or 1-veined, unawned; upper glumes and lower lemmas subequal, membranous, apices rounded, unawned; lower paleas absent or rudimentary; upper lemmas convex, indurate, smooth to slightly rugose, stramineous to dark brown, margins scarious, involute, clasping the paleas; upper paleas indurate, smooth to slightly rugose, stramineous to dark brown. Caryopses orbicular to elliptical, plano-convex or flattened, white, yellow, or brown, x = 10, 12.

Distribution

Conn., N.J., N.Y., Wash., Va., Del., D.C, Wis., W.Va., Pacific Islands (Hawaii), Ont., Fla., N.H., Tenn., N.Mex., Tex., La., Ala., Ark., Miss., Okla., Puerto Rico, S.C., Virgin Islands, N.C., Pa., Mass., R.I., Vt., Nev., Colo., Md., Ga., Utah, Calif., Ill., Ind., Iowa, Kans., Ariz., Idaho, Nebr., Oreg., Ohio, Mo., Minn., Mich., Mont., Ky., S.Dak.

Discussion

Paspalum includes 300-400 species, most of which are native to the Western Hemisphere. Forty-three species are found in the Flora region; twenty-four are native. Paspalum scrobiculatum is grown as a grain in India, and several species are grown as forage plants. There are also many weedy species in the genus. Nineteen of the species growing in the Flora region are introduced, and some of them are weedy. Because weeds are under-represented in most herbaria, the distribution maps of such species probably understate their prevalence.

Key

1 Spikelets solitary, not associated with a naked pedicel or rudimentary spikelets. > 2
2 Panicles with 1-70 branches, if more than 1, the branches racemosely arranged. > 3
3 Branches 7-70, disarticulating at maturity, the axes extending beyond the distal spikelets Paspalum repens
3 Branches 1-6, persistent, terminating in a spikelet. > 4
4 Upper florets olive to dark brown Paspalum scrobiculatum
4 Upper florets pale to stramineous. > 5
5 Axes of panicle branches 0.6-1.3 mm wide Paspalum laeve
5 Axes of panicle branches 1.8-3.3 mm wide. > 6
6 Spikelets 1.7-2.1 mm long; upper lemmas glabrous throughout Paspalum dissectum
6 Spikelets 3.2-4 mm long; upper lemmas with a few short hairs at the apices Paspalum acuminatum
2 Panicles usually composed of a terminal pair of branches, sometimes with 1(-5) additional branches below the terminal pair. > 7
7 Upper glumes pilose on the margins or shortly pubescent on the back. > 8
8 Spikelets 1.3-1.9 mm long; upper glumes pilose along the margins Paspalum conjugatum
8 Spikelets 2.4-3.2 mm long; upper glumes sparsely short pubescent on the back Paspalum distichum
7 Upper glumes glabrous. > 9
9 Spikelets elliptic, their apices acute to acuminate. > 10
10 Plants rhizomatous, not appearing cespitose; usually in brackish to salt marsh habitats Paspalum vaginatum
10 Plants shortly rhizomatous but appearing cespitose; usually in disturbed inland habitats Paspalum almum
9 Spikelets ovate to broadly elliptic, their apices obtuse to broadly acute. > 11
11 Spikelets 2.5-4 mm long; leaf blades flat or conduplicate Paspalum notatum
11 Spikelets 1.9-2.3 mm long; leaf blades flat Paspalum minus
1 Spikelets paired, if only 1 spikelet functional, a naked pedicel or rudimentary, non-functional spikelet present. > 12
12 Spikelets 1-1.3 mm long. > 13
13 Panicle branches 2-6; spikelets elliptic to elliptic-obovate, appressed to the branch axes Paspalum blodgettii
13 Panicle branches 18-50; spikelets ovate, diverging from the branch axes Paspalum paniculatum
12 Spikelets 1.3-4.1 mm long. > 14
14 Margins of upper glumes and lower lemmas ciliate-lacerate and winged or pilose. > 15
15 Upper glumes and lower lemmas ciliate-lacerate, winged Paspalum fimbriatum
15 Upper glumes and lower lemmas pilose. > 16
16 Panicle branches 2-7; spikelets 2.3-4 mm long Paspalum dilatatum
16 Panicle branches (4)10-30; spikelets 1.8-2.8 mm long Paspalum urvillei
14 Margins of upper glumes and lower lemmas neither ciliate-laceerate nor winged, glabrous or pubescent, if pubescent then the hairs not pilose, often glandular, papillose-based, or wrinkled. > 17
17 Upper florets olive to dark brown. > 18
18 Plants aquatic, the culms decumbent, rooting at the nodes; lower glumes often present Paspalum modestum
18 Plants not aquatic or, if aquatic, the culms erect; lower glumes absent. > 19
19 Panicle branches 10-28 or more. > 20
20 Plants annual; axes of panicle branches broadly winged, wings about as wide as the central portion Paspalum boscianum
20 Plant perennial; axes of panicle branches narrowly winged, wings narrower than the central portion. > 21
21 Axes of panicle branches 1-1.7 mm wide; spikelets 1.8-2.4 mm wide Paspalum virgatum
21 Axes of panicle branches 0.5-1.2 mm wide; spikelets 1.1-1.8 mm wide Paspalum conspersum
19 Branches 1-10(28). > 22
22 Plants annual. > 23
23 Spikelets 1.3-1.8 mm wide, broadly elliptical to orbicular, glabrous; panicles with 1-10(28) branches, the axes 0.7-2.3 mm wide Paspalum boscianum
23 Spikelets 1.7-2.4 mm wide, broadly obovate, shortly pubescent; panicles with 1-5 branches, the axes 0.8-1.3 mm wide Paspalum convexum
22 Plants perennial. > 24
24 Plants cespitose, rhizomes sometimes present but not well-developed; culms 100-200 cm tall, stout; panicle branches ascending, divaricate, or reflexed. > 25
25 Leaf blades 7-18 mm wide Paspalum conspersum
25 Leaf blades 2.5-4 mm wide Paspalum plicatulum
24 Plants not cespitose, rhizomatous; culms 10-150 cm tall, varying in thickness; panicle branches ascending. > 26
26 Rhizomes short, indistinct Paspalum plicatulum
26 Rhizomes long, evident. > 27
27 Plants aquatic; upper florets chestnut brown Paspalum wrightii
27 Plants not aquatic; upper florets dark brown Paspalum nicorae
17 Upper florets white, stramineous, or golden brown. > 28
28 Lower lemmas with well-developed ribs over the veins; upper glumes absent Paspalum malacophyllum
28 Lower lemmas not ribbed over the veins; upper glumes present. > 29
29 Panicles with 15-100 branches. > 30
30 Plants annual; upper glumes and lower lemmas rugose Paspalum racemosum
30 Plants perennial; upper glumes and lower lemmas smooth. > 31
31 Plants rhizomatous, not cespitose; branch axes 0.9-1.2 mm wide; panicle branches often arcuate Paspalum intermedium
31 Plants cespitose, not rhizomatous; branch axes 0.3-0.6 mm wide; panicle branches straight. > 32
32 Panicle branches spreading to reflexed (rarely ascending); leaf blades 10-23 mm wide; axes of panicle branches 0.3-0.4 mm wide Paspalum coryphaeum
32 Panicle branches erect to ascending; leaf blades 4.9-6.1 mm wide; axes of panicle branches 0.5-0.6 mm wide Paspalum quadrifarium
29 Panicles with 1-15 branches. > 33
33 Spikelet pairs not imbricate; lower glumes usually present Paspalum bifidum
33 Spikelet pairs imbricate; lower glumes absent or present. > 34
34 Spikelets 1.3-2.5 mm long. > 35
35 Upper glumes, usually also the lower lemmas, shortly pubescent. > 36
36 Lower glumes present Paspalum langei
36 Lower glumes absent. > 37
37 Panicles both terminal and axillary, the axillary panicles partially or completely enclosed by the subtending leaf sheath Paspalum setaceum
37 Panicles all terminal. > 38
38 Leaf blades involute; culms 80-110 cm tall Paspalum laxum
38 Leaf blades flat; culms 20-75 cm tall. > 39
39 Spikelets 1.3-2 mm long, 0.7-1 mm wide, elliptic; upper glumes and lower lemmas 5-veined; culm bases swollen Paspalum caespitosum
39 Spikelets 2-2.5 mm long, 1.4-1.6 mm wide, ovate; upper glumes and lower lemmas 3-veined; culm bases not swollen Paspalum virletii
35 Upper glumes and lower lemmas glabrous. > 40
40 Panicles both terminal and axillary, the axillary panicles partially or completely enclosed by the subtending leaf sheath Paspalum setaceum
40 Panicles all terminal. > 41
41 Upper panicle branches erect Paspalum monostachyum
41 Upper panicle branches spreading to ascending. > 42
42 Leaf blades mostly involute; plants of sandy or rocky areas, usually on the coast Paspalum pleostachyum
42 Leaf blades mostly flat; plants of inland areas or, if coastal, then in marshy areas. > 43
43 Upper glumes and lower lemmas 3-veined. > 44
44 Leaf blades usually conduplicate, 2.2-8.3 mm wide Paspalum praecox
44 Leaf blades usually flat, 5-10 mm wide Paspalum virletii
43 Upper glumes and lower lemmas 5-veined. > 45
45 Axes of panicle branches 0.2-0.5 mm wide; ligules 0.2-0.4 mm long Paspalum caespitosum
45 Axes of panicle branches 1.5-2 mm wide; ligules 2.2-4.7 mm long Paspalum lividum
34 Spikelets 2.5-4.1 mm long. > 46
46 Upper glumes, and usually lower lemmas, pubescent. > 47
47 Lower glumes present Paspalum langei
47 Lower glumes absent. > 48
48 Leaf blades 2-5 mm wide; upper glumes and lower lemmas abundantly pubescent, most hairs longer than 0.1 mm; spikelets elliptic Paspalum bartwegianum
48 Leaf blades 4-18 mm wide; upper glumes and lower lemmas glabrous or sparsely pubescent, the hairs shorter than 0.1 mm; spikelets obovate to elliptic Paspalum pubiflorum
46 Upper glumes, and usually lower lemmas, glabrous. > 49
49 Upper florets golden brown. > 50
50 Plants not rhizomatous; culms decumbent and rooting at the lower nodes; spikelets 1.3-1.6 mm wide; lower lemmas 5-7-veined; lower glumes often present Paspalum modestum
50 Plants rhizomatous; culms erect, not rooting at the lower nodes; spikelets 1.9-3.1 mm wide; lower lemmas 3-veined. > 51
51 Panicle branches 1-6; upper glumes 5-veined; leaf blades 3-18 mm wide Paspalum floridanum
51 Panicle branches 1-3; upper glumes 3-veined; leaf blades 3-4 mm wide Paspalum unispicatum
49 Upper florets stramineous to pale, but not golden brown. > 52
52 Terminal panicle branches erect. > 53
53 Blades involute; upper glumes 1-veined Paspalum monostachyum
53 Blades flat; upper glumes 3-veined Paspalum unispicatum
52 Terminal panicle branches spreading to ascending. > 54
54 Spikelets 2.2-2.6 mm long. > 55
55 Spikelets 1.2-1.5 mm wide, elliptic to obovate Paspalum lividum
55 Spikelets 2-2.8 mm wide, orbicular to suborbicular Paspalum praecox
54 Spikelets 2.6-4.1 mm long. > 56
56 Plants decumbent, rooting at the lower nodes, not rhizomatous; spikelets obovate to elliptic Paspalum pubiflorum
56 Plants rhizomatous, neither decumbent nor rooting at the lower nodes; spikelets orbicular to elliptic. > 57
57 Spikelets 2.1-3.1 mm long, 2-2.8 mm wide, orbicular to suborbicular; upper glumes 3-veined; leaf blades conduplicate Paspalum praecox
57 Spikelets 2.9-4.1 mm long, 1.9-3.1 mm wide, suborbicular to elliptic; upper glumes 5-veined; leaf blades flat Paspalum floridanum
... more about "Paspalum"
Charles M. Allen +  and David W. Hall +
Conn. +, N.J. +, N.Y. +, Wash. +, Va. +, Del. +, D.C +, Wis. +, W.Va. +, Pacific Islands (Hawaii) +, Ont. +, Fla. +, N.H. +, Tenn. +, N.Mex. +, Tex. +, La. +, Ala. +, Ark. +, Miss. +, Okla. +, Puerto Rico +, S.C. +, Virgin Islands +, N.C. +, Pa. +, Mass. +, R.I. +, Vt. +, Nev. +, Colo. +, Md. +, Ga. +, Utah +, Calif. +, Ill. +, Ind. +, Iowa +, Kans. +, Ariz. +, Idaho +, Nebr. +, Oreg. +, Ohio +, Mo. +, Minn. +, Mich. +, Mont. +, Ky. +  and S.Dak. +
banks1966a +, pohl1994c +  and unknown2000a +
Gramineae +
Paspalum +
Poaceae tribe Paniceae +