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rescue brome, rescue grass, rescuegras

brome mou, lesser soft brome, lopgrass, soft brome, soft chess

Habit Plants annual, biennial, or perennial; loosely cespitose or tufted. Plants annual or biennial.
Culms

30-120 cm tall, 2-4 mm thick, erect or decumbent.

2-70 cm, erect or ascending.

Sheaths

usually densely, often retrorsely, hairy, hairs sometimes confined to the throat;

auricles absent;

ligules 1-4 mm, glabrous or pilose, obtuse, lacerate to erose;

blades 4-30 cm long, 3-10 mm wide, flat, glabrous or hairy on both surfaces.

Panicles

9-28 cm, usually open, erect or nodding;

lower branches shorter than 10 cm, 1-4 per node, spreading or ascending, with up to 5 spikelets variously distributed.

1-13 cm long, 1-4 cm wide, erect, usually ovoid, open, becoming dense, occasionally reduced to 1 or 2 spikelets;

branches shorter than the spikelets, ascending to erect, straight or almost so.

Spikelets

(17)20-40 mm, shorter than at least some pedicels and branches, elliptic to lanceolate, strongly laterally compressed, not crowded or overlapping, with 4-12 florets.

(11)14-20(23) mm, lanceolate, terete to moderately laterally compressed;

florets 5-10, bases concealed at maturity;

rachilla internodes concealed at maturity.

Glumes

smooth or scabrous, glabrous or pubescent;

lower glumes 7-12 mm, 5-7(9)-veined;

upper glumes 9-17 mm, 7-9(11)-veined, shorter than the lowest lemma;

lemmas 11-20 mm, lanceolate, laterally compressed, strongly keeled, usually glabrous, sometimes pubescent distally, smooth or scabrous, 9-13-veined, veins often raised and riblike, margins sometimes conspicuous, hyaline, whitish or partly purplish, apices entire or toothed, teeth acute, shorter than 1 mm;

awns absent or to 10 mm;

anthers 0.5-1 mm in cleistogamous florets, 2-5 mm in chasmogamous florets.

pilose or glabrous;

lower glumes 5-7 mm, 3-5-veined;

upper glumes 6.5-8 mm, 5-7-veined;

lemmas 6.5-11 mm long, 3-5 mm wide, lanceolate, chartaceous, antrorsely pilose to pubescent, or glabrous proximally or throughout, 7-9-veined, lateral veins prominently ribbed, rounded over the midvein, hyaline margins abruptly or bluntly angled, not inrolled at maturity, apices acute, bifid, teeth shorter than 1 mm;

awns 6-8 mm, usually arising less than 1.5 mm below the lemma apices, straight to recurved at maturity;

anthers 0.6-1.5 mm.

Caryopses

equaling or shorter than the paleas, thin, weakly inrolled to flat.

Lower

sheaths densely, often retrorsely, pilose;

upper sheaths pubescent or glabrous;

ligules 1-1.5 mm, hairy, obtuse, erose;

blades 2-19 cm long, 1-4 mm wide, abaxial surfaces glabrous or hairy, adaxial surfaces hairy.

2n

= 42.

= 28.

Bromus catharticus

Bromus hordeaceus

Distribution
from FNA
AL; AR; AZ; CA; CO; DC; FL; GA; IA; IL; KS; KY; LA; MD; MO; MS; NC; ND; NE; NJ; NM; NV; NY; OH; OK; OR; PA; SC; SD; TN; TX; UT; VA; HI; AB; NF; ON
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; AR; AZ; CA; CO; CT; DE; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MO; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; WA; WI; WY; HI; AB; BC; LB; NB; NS; NT; ON; QC; YT; Greenland
[WildflowerSearch map]
[BONAP county map]
Discussion

Bromus hordeaceus is native to southern Europe and northern Africa. It is weedy, growing in disturbed areas such as roadsides, fields, sandy beaches, and waste places, and can be found in many locations in the Flora region, with the exception of the central Canadian provinces and most of the southeastern United States. Its origin is obscure. Ainouche et al. (1999) reviewed various suggestions, and concluded that at least one of its diploid ancestors may have been an extinct or undiscovered species related to B. caroli-henrici, a diploid species.

The four subspecies are usually morphologically distinct. Ainouche et al. (1999), however, found no evidence of genetic differentiation among them.

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

Key
1. Awns absent or to 3.5 mm long
var. catharticus
1. Awns (5)6-10 mm long
var. elatus
1. Lemmas (7)8-11 mm long, usually pubescent or pilose.
→ 2
2. Awns more than 0.1 mm wide at the base, straight, erect; culms (3)10-70 cm long
subsp. hordeaceus
2. Awns less than 0.1 mm wide at the base, often divaricate or recurved at maturity; culms 15-25(60) cm long
subsp. molliformis
1. Lemmas 6.5-8(9) mm long, glabrous or pubescent.
→ 3
3. Culms (3)10-70 cm long; panicles up to 10 cm long, usually with more than 1 spikelet; lemmas usually glabrous; caryopses usually as long as the paleas; habitat various
subsp. pseudothomineii
3. Culms 2-16 cm long; panicles 1-3 cm long, often reduced to 1 spikelet; lemmas pubescent or glabrous; caryopses shorter than the paleas; plants of maritime or lacustrine sands
subsp. thotninei
Source FNA vol. 24, p. 199. FNA vol. 24, p. 232.
Parent taxa Poaceae > subfam. Pooideae > tribe Bromeae > Bromus > sect. Ceratochloa Poaceae > subfam. Pooideae > tribe Bromeae > Bromus > sect. Bromus
Sibling taxa
B. aleutensis, B. anomalus, B. arenarius, B. arizonicus, B. arvensis, B. berteroanus, B. briziformis, B. carinatus, B. caroli-henrici, B. ciliatus, B. commutatus, B. danthoniae, B. diandrus, B. erectus, B. frondosus, B. grandis, B. hallii, B. hordeaceus, B. inermis, B. japonicus, B. kalmii, B. laevipes, B. lanatipes, B. lanceolatus, B. latiglumis, B. lepidus, B. madritensis, B. maritimus, B. mucroglumis, B. nottowayanus, B. orcuttianus, B. pacificus, B. polyanthus, B. porteri, B. pseudolaevipes, B. pubescens, B. pumpellianus, B. racemosus, B. ramosus, B. richardsonii, B. riparius, B. rubens, B. scoparius, B. secalinus, B. sitchensis, B. squarrosus, B. sterilis, B. suksdorfii, B. tectorum, B. texensis, B. vulgaris
B. aleutensis, B. anomalus, B. arenarius, B. arizonicus, B. arvensis, B. berteroanus, B. briziformis, B. carinatus, B. caroli-henrici, B. catharticus, B. ciliatus, B. commutatus, B. danthoniae, B. diandrus, B. erectus, B. frondosus, B. grandis, B. hallii, B. inermis, B. japonicus, B. kalmii, B. laevipes, B. lanatipes, B. lanceolatus, B. latiglumis, B. lepidus, B. madritensis, B. maritimus, B. mucroglumis, B. nottowayanus, B. orcuttianus, B. pacificus, B. polyanthus, B. porteri, B. pseudolaevipes, B. pubescens, B. pumpellianus, B. racemosus, B. ramosus, B. richardsonii, B. riparius, B. rubens, B. scoparius, B. secalinus, B. sitchensis, B. squarrosus, B. sterilis, B. suksdorfii, B. tectorum, B. texensis, B. vulgaris
Subordinate taxa
B. catharticus var. catharticus, B. catharticus var. elatus
B. hordeaceus subsp. hordeaceus, B. hordeaceus subsp. molliformis, B. hordeaceus subsp. pseudothomineii, B. hordeaceus subsp. thotninei
Synonyms Ceratochloa unioloides, B. willdenowii, B. unioloides B. mollis
Name authority Vahl L.
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