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rescue brome, rescue grass, rescuegras

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

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

annual, not woody, not branching above the base;

internodes usually hollow, rarely solid.

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.

closed, margins united for most of their length;

collars without tufts of hair on the sides;

auricles sometimes present;

ligules membranous, sometimes shortly ciliate, those of the upper and lower cauline leaves usually similar;

pseudopetioles absent;

blades linear to narrowly lanceolate, venation parallel, cross venation not evident, without arm or fusoid cells, cross sections non-Kranz, epidermes without microhairs, not papillate.

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.

Inflorescences

usually terminal panicles, sometimes reduced to racemes in depauperate plants;

disarticulation above the glumes and beneath each floret.

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.

5-80 mm, not viviparous, terete to laterally compressed, with 3-30 bisexual florets, distal florets sometimes reduced;

rachillas prolonged beyond the bases of the distal florets.

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.

usually unequal, rarely more or less equal, exceeded by the distal florets, usually longer than 1/4 the length of the adjacent florets, lanceolate, 1-9(11)-veined;

florets terete to laterally compressed;

calluses glabrous, not well developed;

lemmas lanceolate to ovate, rounded or keeled over the midvein, herbaceous to coriaceous, 5-13-veined, veins converging somewhat distally, apices usually minutely bilobed to bifid, rarely entire, usually awned, sometimes unawned, awns unbranched, terminal or subterminal, usually straight, sometimes geniculate;

paleas usually shorter than the lemmas;

lodicules 2, glabrous, not veined;

anthers 3;

ovaries with hairy apices;

styles 2, bases free.

Caryopses

narrowly ellipsoid to linear, longitudinally grooved;

hila linear;

embryos about 1/6 the length of the caryopses.

x

= 7.

2n

= 42.

Bromus catharticus

Poaceae tribe bromeae

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
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[BONAP county map]
Discussion

There are three genera in the Bromeae. One genus, Bromus, grows in the Flora region. The tribe was included in the Festuceae Dumort. [= Poeae] by earlier agrostologists (e.g., Hitchcock 1951) because it has paniculate inflorescences, spikelets with more than 1 floret, and glumes that are shorter than the lemmas. It is now considered to be most closely related to the Triticeae. This is indicated by the pubescent apices of the ovaries and simple endosperm starch grains. It is further supported by data from serology, nucleic acid sequences, and seedling development. These data do not support a close relationship between the Bromeae and Brachypodium, a genus that has sometimes been included in the tribe.

(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
Source FNA vol. 24, p. 199. FNA vol. 24, p. 192. Author: Mary E. Barkworth;.
Parent taxa Poaceae > subfam. Pooideae > tribe Bromeae > Bromus > sect. Ceratochloa Poaceae > subfam. Pooideae
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
Subordinate taxa
B. catharticus var. catharticus, B. catharticus var. elatus
Synonyms Ceratochloa unioloides, B. willdenowii, B. unioloides
Name authority Vahl Dumort.
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