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Paspalum
1. Spikelets < or equal 2 mm long (rarely longer in
P. setaceum)…3
1. Spikelets > 2 mm long…2
2. Spikelets long-silky, the silk much exceeding
the spikelets… (Spikelets with pilose margins in P. dilitatum
also, but this species not known in Palm Beach or Martin counties)
2. Spikelets glabrous or with short pubescence (not
with long silky hairs)…5
3. Inflorescence branches forming an even Y (may
have an additional branch below that)… (spikelets
usually ca. 1.3 mm long, silky)
3. Inflorescence not forming a Y (or so,
but the peduncles at the base of each raceme unequal)…4
4. Spikelets ca. 1.3 mm long… (spikelets
glandular-pubescent)
4. Spikelets 1.4-2 mm long (rarely longer)… (often with axillary inflorescences)
5. Seashore or brackish-shore species (also used
for lawn as “Seashore Paspalum”). Spikelets boat-shaped or lanceolate… (strongly stoloniferous.
Leaves with homogeneous adaxial
papillae vs. dimorphic in Sporobolus virginicus, ligules with
long cilia) (a similar species is P. distichum, but this species
is less maritime, and not recorded in our area)
5. Plants not maritime. Spikelets orbicular to
broadly elliptic or ovate, the tip rounded or acute…6
6. Leaves terete. Glume with 1 vein…
6. Leaves flat or involute. Upper (usually only) glume with 3 or more veins…7
7. Spikelets solitary...12
7. Spikelets paired. Inflorescence branches
solitary, or racemose…8
8. Upper glume 3-veined. Spikelet nearly orbicular,
> 2 mm wide… (the veins 3 + 3 vs. 3 + 5 in P. laeve
and racemes 4-6 vs. 3-4 in P. laeve, which is not reported for
our area)
8. Upper glume 5-veined. Spikelet elliptic,
usually < 2 mm wide (can go to 3 mm wide in P. floridanum)…9
9. Spikelets mostly 3-4 mm long, 2-3 mm wide… (sheaths and adaxial leaf blades tending to be villous)
9. Spikelets mostly 3 or fewer mm long, narrower
than 2 mm…10
10. Spikelets 2-2.2 mm long…
(rachis very broad, 2 mm)
10. Spikelets > 2.2 mm long…11
11. Lemma 5-veined. Spikelet 1.4-1.8 mm wide… (rachis < 1 mm wide; spikelets pubescent)
11. Lemma 3-veined. Spikelet 1-1.3 mm wide… (inflorescence branches usually > 6; leaf blades
marginally serrulate)
12. Upper inflorescence branches often forming a
nearly even Y...
(1-3 branches sometimes present below the terminal pair. Bahia
grass - spikelets 2.5-3.5 mm long - a turf species)
12. Upper inflorescence branches usually 3 or 4 and
racemose (branching from a central axis)...
(compare with P. praecox which has paired spikelets, veins 3 + 3 vs. 3 +
5, and racemes 4-6 vs. 3-4)
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