Tragus berteronianus Schult.

bur grass, Bertero goatgrass


Info

Subfamily: Chloridoideae
Genus etymology: Tragus = honorific for Hieronymus Bock (1498–1554) whose name translates to Greek as Tragus (male goat)
Species etymology: berteronianus = honorific for Carlo Guiseppe Bertero (1789–1831)
Photosynthetic type: C4 (warm season)
Nativity: naturalized - accidental
First recorded in Hawaiʻi: 1935

Map

 Distribution of Tragus berteronianus in Hawaiʻi.

Inflorescence

Tragus berteronianus Inflorescence

Plant

Tragus berteronianus Plant
Tragus berteronianus Plant

Habit

Tragus berteronianus Habit
Tragus berteronianus Habit
Tragus berteronianus Habit
Tragus berteronianus Habit
Tragus berteronianus Habit

Spikelets

Tragus berteronianus Spikelets
Tragus berteronianus Spikelets
Tragus berteronianus Spikelets
Tragus berteronianus Spikelets
Tragus berteronianus Spikelets
Tragus berteronianus Spikelets

Collar

Tragus berteronianus Collar

Description

Loosely tufted annual; culms 5–60 cm. high, erect or ascending. Leaf-blades 1–6 cm. long, 2–5 mm. wide. Inflorescence 2–15 cm. long, compactly cylindrical, congested; clusters plump, the tips incurved, comprising 2 spikelets of which the upper is smaller and borne upon a distinct internode 0.3–0.7 mm. long. Spikelets (lower) 2–3 mm. long; upper glume 5-nerved, the prickles turgid to bulbous in their lower half and hooked at the tip. Fig. 108.
(Description source: Clayton, W.D. 1970. Flora of Tropical East Africa. Gramineae (Part 1). Crown Agents for Oversea Governments and Administrations, London. 176 pp. )

Annual up to 20 cm high. Inflorescence 2–7.5 cm long; racemelets comprising 2 spikelets separated by a short but distinct internode, the upper shorter than the lower, the rhachis not prolonged. Spikelets 2–3 mm long, acute; upper glume 5-nerved, the prickles hooked and with turgid or swollen base.
(Description source: Cope, T.A, (1995) Flora Somalia, Vol 4. Royal Botanical Gardens, Kew, London. 312 pp. )

Annual up to 45 cm tall, erect or geniculately ascending; leaf laminas 1.5–5.5 cm × 2–5 mm, flat or undulate, glaucous, the margins thickened, whitish, pectinate with bulbous-based hairs or barbellate.Inflorescence 3.5–15 cm long, compactly cylindrical and congested; racemelets comprising 2 fertile spikelets borne on a short peduncle and separated by a distinct internode 0.3–0.7 mm long.Spikelets 1.8–3 mm long; superior glume prominently 5-nerved, the nerves bearing hooked, bulbous-based prickles, glabrous between the nerves; anthers 0.4–0.6 mm long.
(Description source: Pope, G.V. (ed). 1999. Flora Zambesiaca. Volume 10. Part 2. Kew, London. 261 pp. )

Plants annual. Culms (2)3.5-45 cm. Ligules 0.5-1 mm; blades (0.5)0.7-8.5 cm long, 1.2-5 mm wide, glabrous. 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. Proximal spikelets (1.8)2^.3 mm; second spikelets (0.8)1-3.9 mm, some¬times 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. Caryopses (0.9)1.2-2 mm long, 0.4-0.8 mm wide. 2n = 20.
(Description source: Barkworth, M.E., Capels, K.M., Long, S. & Piep, M.B. (eds.) 2003. Flora of North America, north of Mexico. Volume 25. Magnoliophyta: Commelinidae (in part): Poaceae, Part 2. Oxford University Press, New York. 783 pp. http://floranorthamerica.org/Tragus_berteronianus )

Annuals; culms erect or decumbent at base, 1-2.5 dm tall, pubescent. below racemes. Sheaths 1-3 cm long, glabrous, striate, the uppermost often dilated; ligule ciliate, 0.5-0.7 mm long; blades thick, firm, 1.5-2 cm long or the uppermost vestigial, 1-3 mm wide, margins undulate, cartilaginous, pubescent with stiff white hairs. Racemes 3-7 cm long, 4-5 mm in diameter, often enclosed within the uppermost Sheaths, rachis slender, pubescent; burs 2-3 mm long, beaked, pedicels pubescent, up to 0.5 mm long; spikelets 2 per bur; first glume absent, second glumes of the 2 spikelets forming the halves of a bur, convex, 3- nerved, the nerves bearing a row of stout hooked spines on either side; lemma ca. 2 mm long, apex acute, sparsely pubescent; palea 1.5-2 mm long, glabrous, apex acute. Caryopsis golden brown, 1.2-1.5 mm long. [2n = 20.]
(Description source: O’Connor, P.J. 1990. Poaceae, pp. 1481–1604. In: Wagner W.L., Herbst D.R. & Sohmer S.H. (eds.)., Manual of the flowering plant of Hawaiʻi. Vol. 2. University of Hawaii Press & Bishop Museum Press, Honolulu )