Flora of North America species comparison

The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Bromus catharticus

Bromus sect. Ceratochloa

rescue brome, rescue grass, rescuegras
Habit Plants annual, biennial, or perennial; loosely cespitose or tufted. Plants annual, biennial, or perennial.
Culms

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

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.

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.

elliptic to lanceolate, strongly laterally compressed, with 3-12 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.

Lower

glumes 3-7(9)-veined;

upper glumes 5-9(11)-veined;

lemmas lanceolate, laterally compressed, strongly keeled, at least distally, apices entire or with acute teeth, teeth shorter than 1 mm;

awns straight, erect to slightly divaricate.
2n

= 42.

Bromus catharticus

Bromus sect. Ceratochloa
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]
Discussion

Bromus sect. Ceratochloa is native to North and South America, and contains about 25 species. It is marked by polyploid complexes; the major one in North America is the Bromus carinatus complex. This treatment recognizes six species in the complex: B. aleutensis, B. arizonicus, B. carinatus, B. maritimus, B. polyanthus, and B. sitchensis. The lowest chromosome number known for members of this complex is 2n= 28, found in B. carinatus; the highest is 2n = 84, found in B. arizonicus. The remaining species are hexaploids with 2n = 42, or octoploids with 2n = 56. One other species in the section, B. catharticus, has been introduced from South America and is also part of a polyploid complex.

There is morphological intergradation among the species recognized here, and some evidence that these intermediates are sometimes partially fertile (Harlan 1945a, 1945b; Stebbins and Tobgy 1944; Stebbins 1947). Stebbins and Tobgy (1944) commented that partial hybrid sterility between plants placed in different species on the basis of their morphology "supports the recognition of more than one species among the octoploid members of the complex," but later Stebbins (1981) stated that "... all the North American octoploids. . . should be united into a single species, in spite of the barriers of hybrid sterility that separate 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 unawned or with awns to 3.5 mm long; lemmas usually glabrous, sometimes pubescent distally, veins prominent for most of their length
B. catharticus
1. Lemmas awned, awns (2)4-17 mm long; lemmas pubescent or glabrous, veins obscure or prominent.
→ 2
2. Lower panicle branches shorter than 20 cm, with 1-3 spikelets on the distal 1/2, sometimes confined to the tips; culms 3-7 mm thick.
→ 3
3. Lower panicle branches shorter than 20 cm, spreading to drooping
B. sitchensis
3. Lower panicle branches shorter than 10 cm, stiffly ascending
B. aleutensis
2. Lower panicle branches usually shorter than 10 cm, with 1-5 spikelets variously distributed; culms less than 4 mm thick.
→ 4
4. Upper glume about as long as the lowest lemma in each spikelet; lemmas glabrous or pubescent distally or throughout, the marginal hairs, if present, longer than those elsewhere
B. arizonicus
4. Upper glume shorter than the lowest lemma in each spikelet; lemmas glabrous or pubescent only on the margins or throughout, if throughout, the marginal hairs similar in length to those elsewhere.
→ 5
5. Panicles dense; spikelets crowded, overlapping, usually longer than the pedicels and branches; culms 20-70 cm tall, sometimes geniculate at the base; blades glabrous; ligules 1-6 mm long
B. maritimus
5. Panicles loose to compact; spikelets not crowded or overlapping, shorter than at least some pedicels and branches; culms 30-120(180) cm tall, erect or decumbent; blades glabrous or hairy; ligules 1-4 mm long.
→ 6
6. Lemmas and sheath throats glabrous
B. polyanthus
6. Lemmas and/or sheath throats with hairs.
→ 7
7. Lemmas 9-13-veined, veins often raised and riblike distally or throughout
B. catharticus
7. Lemmas 7-9-veined, veins usually not raised or riblike
B. carinatus
Source FNA vol. 24, p. 199. FNA vol. 24, p. 199.
Parent taxa Poaceae > subfam. Pooideae > tribe Bromeae > Bromus > sect. Ceratochloa Poaceae > subfam. Pooideae > tribe Bromeae > 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
Subordinate taxa
B. catharticus var. catharticus, B. catharticus var. elatus
B. aleutensis, B. arizonicus, B. carinatus, B. catharticus, B. maritimus, B. polyanthus, B. sitchensis
Synonyms Ceratochloa unioloides, B. willdenowii, B. unioloides
Name authority Vahl (P. Beauv.) Griseb.
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).



Type/paste one or more Latin names into the boxes above; matching taxa will show up below the box as you type. You can use the up/down arrow keys to move through the list.

(If the plant you're looking for doesn't show up in the auto-complete list, that means it either isn't described in Flora of North America yet, or it's listed under a synonym. And please note that Flora of North America is still missing several plant families, including Fabaceae, Apiaceae, Boraginaceae, and Polemoniaceae.)

Choose a data source: Flora of North America, OregonFlora

The species comparison tool is brought to you by:
Northwest Wildflowers