Flora of North America species comparison

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Taeniatherum caput-medusae

medusa-head, medusahead rye
Culms

(5)10-55(70) cm.
Spikes

1.2-6 cm.
Spikelets

6-45 mm;

glumes (5)7-80 mm, awnlike, erect to reflexed.
Caryopses

4-5.2 mm.
Bisexual florets

lemmas 5.5-8 mm, awns (20) 30-110 mm, divergent;

anthers 0.8-1 mm.
Auricles

0.1-0.5 mm, rarely absent;

ligules 0.2-0.6 mm;

blades (0.2) 0.7-2.5 mm wide, flat to involute.
2n

= 14.

Taeniatherum caput-medusae
Distribution
from USDA
[WildflowerSearch map]
[BONAP county map]
Discussion

Taeniatherum caput-medusae is native from Portugal and Morocco east to Kyrgyzstan. It usually grows on stony soils, and flowers from May–June (July). It is an aggressive invader of disturbed sites in the western United States, where it has become a serious problem on rangelands. It has been found as a rare introduction at several sites in the eastern United States, but may not persist there. It is listed as a noxious weed by the U.S. Department of Agriculture.

Frederiksen (1986) recognized three subspecies within Taeniatherum caput-medusae, distinguishing among them on the basis of morphology and geography. Plants in the Flora region belong to Taeniatherum caput-medusae (L.) Nevski subsp. caput-medusae. It differs from the other two subspecies in its longer glumes and shorter lemmas.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Source FNA vol. 24, p. 258.
Parent taxa Poaceae > subfam. Pooideae > tribe Triticeae > Taeniatherum
Name authority unknown
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



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