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spike bur grass, spike burr grass

stalk bur grass

Habit Plants annual. Plants annual.
Culms

(2)3.5-45 cm.

5-40 cm.

Panicles

(1)2-13 cm long, (3)4-8 mm wide;

rachises pubescent;

branches (0.5)0.7-2.7 mm, pubescent, with 2(3) spikelets, axes occasionally extending past the distal spikelets;

proximal internodes 0.2-0.6(0.7) mm, shorter than the second internodes.

(1.5)2-11 cm long, 7-13 mm wide;

rachises pubescent;

branches 2.1-4.8 mm, pubescent, with (2)3-5 spikelets, axes extending past the distal spikelets;

proximal internodes 0.5-1.8 mm, longer than second internodes.

Caryopses

(0.9)1.2-2 mm long, 0.4-0.8 mm wide.

1.7-2.3 mm long, 0.6-0.8 mm wide.

Ligules

0.5-1 mm;

blades (0.5)0.7-8.5 cm long, 1.2-5 mm wide, glabrous.

0.5-1.3 mm;

blades (0.5)1-5.5 cm long, 1.5-4 mm wide, glabrous.

Proximal

spikelets (1.8)2^.3 mm;

second spikelets (0.8)1-3.9 mm, sometimes sterile.

spikelets 3.8-6.6 mm;

second spikelets (2.3)2.9-6.6 mm;

third and fourth spikelets 0.8-4.2 mm;

distal spikelets sterile.

Lower

glumes 0.1-0.6 mm, membranous, minutely pubescent;

upper glumes 1.8-4.3 mm, minutely pubescent, 5-veined, rarely with 1-2 additional veins adjacent to the midvein;

glume projections (4)6-14, in 5 rows, (0.2)0.3-1 mm, uncinate;

lemmas (1.5)1.8-3.1 mm, sparsely pubescent on the back, midveins occasionally excurrent to 0.6 mm;

paleas (1.3)1.5-2.4 mm;

anthers 3, 0.4-0.6 mm, yellow, occasionally purple-or green-tinged.

glumes 0.7-1.1 mm, glabrous or minutely pubescent;

upper glumes 3.8-6.6 mm, 7-veined, minutely pubescent;

glume projections 6-11, in (5)6-7 rows, (0.2)0.6-1.3 mm, usually uncinate;

lemmas 3.2-4 mm, sparsely pubescent on the back, midveins occasionally excurrent to 4 mm;

paleas 2.3-3.1 mm;

anthers 3, 0.6-0.8 mm, yellow.

2n

= 20.

= 40.

Tragus berteronianus

Tragus racemosus

Distribution
from FNA
AZ; MA; ME; NM; NY; SC; TX; VA; HI; PR; Virgin Islands
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; MA; MD; ME; NC; NJ; NY; PA
[BONAP county map]
Discussion

Tragus berteronianus is native to Africa and Asia, and is now established in Arizona, New Mexico, and Texas. It was collected in Maine, Massachusetts, New York, and Virginia in the nineteenth century, and Virginia in 1959.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Tragus racemosus is native from the Mediterranean region to southwest Asia, but now grows in the United States, primarily in Cochise and Pima Counties, Arizona. It was collected in Maine, Pennsylvania, New York, and North Carolina in the late nineteenth century, but does not appear to be established in these states. Reports for New Mexico and Texas appear to reflect confusion with T. berteronianus.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 25, p. 280. FNA vol. 25, p. 281.
Parent taxa Poaceae > subfam. Chloridoideae > tribe Cynodonteae > Tragus Poaceae > subfam. Chloridoideae > tribe Cynodonteae > Tragus
Sibling taxa
T. australianus, T. heptaneuron, T. racemosus
T. australianus, T. berteronianus, T. heptaneuron
Name authority Schult. (L.) All.
Web links 
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