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Vascular Plants of California
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Munroa squarrosa

Higher Taxonomy
Family: Poaceae (Gramineae)View DescriptionDichotomous Key
Habit: Annual to woody perennial herb; roots generally fibrous. Stem: generally round, hollow; nodes swollen, solid. Leaf: alternate, 2-ranked, generally linear, parallel-veined; sheath generally open; ligule membranous or hairy, at blade base. Inflorescence: various (of generally many spikelets). Spikelet: glumes generally 2; florets (lemma, palea, flower) 1--many; lemma generally membranous, sometimes glume-like; palea generally +- transparent, +- enclosed by lemma. Flower: generally bisexual, minute; perianth vestigial; stamens generally 3; stigmas generally 2, generally plumose. Fruit: grain, sometimes achene- or utricle-like.
Genera In Family: 650--900 genera; +- 10550 species: worldwide; greatest economic importance of any family (wheat, rice, maize, millet, sorghum, sugar cane, forage crops, ornamental, weeds; thatching, weaving, building materials). Note: Generally wind-pollinated. Achnatherum, Ampelodesmos, Hesperostipa, Nassella, Piptatherum, Piptochaetium, Ptilagrostis moved to Stipa; Elytrigia, Leymus, Pascopyrum, Pseudoroegneria, Taeniatherum to Elymus; Hierochloe to Anthoxanthum; Lolium, Vulpia to Festuca; Lycurus to Muhlenbergia; Monanthochloe to Distichlis; Pleuraphis to Hilaria; Rhynchelytrum to Melinis. The following taxa (in genera not included here), recorded in California from historical collections or reported in literature, are extirpated, lacking vouchers, or not considered naturalized: Acrachne racemosa (Roth) Ohwi, Allolepis texana (Vasey) Soderstr. & H.F. Decker, Amphibromus nervosus (Hook. f.) Baill., Axonopus affinis Chase, Axonopus fissifolius (Raddi) Kuhlm., Coix lacryma-jobi L., Cutandia memphitica (Spreng.) K. Richt., Dinebra retroflexa (Vahl) Panz., Eremochloa ciliaris (L.) Merr., Eustachys distichophylla (Lag.) Nees, Gaudinia fragilis (L.) P. Beauv., Miscanthus sinensis Andersson, Neyraudia arundinacea (L.) Henrard, Phyllostachys aurea Rivière & C. Rivière, Phyllostachys bambusoides Siebold & Zuccarini, Rottboellia cochinchinensis (Lour.) Clayton, Schedonnardus paniculatus (Nutt.) Branner & Coville, Schizachyrium cirratum (Hack.) Wooton & Standl., Schizachyrium scoparium (Michx.) Nash, Themeda quadrivalvis (L.) Kuntze, Thysanolaena latifolia (Hornem.) Honda, Tribolium obliterum (Hemsl.) Renvoize, Zea mays L., Zizania palustris L. var. interior (Fassett) Dore, Zoysia japonica Steud. Paspalum pubiflorum E. Fourn., Paspalum quadrifarium Lam., are now reported for southern California (J Bot Res Inst Texas 4:761--770). See Glossary p. 30 for illustrations of general family characteristics.
eFlora Treatment Author: James P. Smith, Jr., except as noted
Scientific Editor: James P. Smith, Jr., J. Travis Columbus, Dieter H. Wilken.
Genus: MunroaView Description 

Habit: Annual, mat-forming. Stem: stolon-like, 2--8 cm, terminating in clusters of leaves from which new stems arise; stem to 15 cm. Leaf: mostly basal; sheath hairy-tufted at throat; ligule hairy; blade linear, generally inrolled, occasionally flat or folded, sharply pointed, margins white, thickened. Inflorescence: terminal, head-like; spikelets 2--4, subsessile to pedicelled, clustered, subtended by leafy bract; axis breaking above glumes or below bract. Spikelet: laterally compressed; florets 2--10, lower florets bisexual or pistillate; terminal florets sterile; glumes < spikelet, 1-veined, unawned; lower glumes generally present, upper absent or reduced on terminal spikelet; lemma pubescent or scabrous, membranous or leathery, 3-veined, lateral vein tips short-awned, tips +- 2-lobed; palea glabrous, smooth; anthers 2 or 3, yellow; styles elongate, stigmas 2 or 3. Fruit: dorsally compressed.
Species In Genus: 5 species: western hemisphere. Etymology: (W. Munro, English agrostologist, 1818--1880) Note: Closest relatives are thought to be Blepharidachne and Dasyochloa, both stoloniferous, mat-forming species with leafy-bracted panicles. Munroa differs from both in its annual habit.
eFlora Treatment Author: Jesús Valdés-Reyna
Reference: Valdés-Reyna 2003 FNANM 25:51--52
Unabridged Reference: Parodi 1934 Revista Mus La Plata Secc Bot 34:171--193; Sanchez 1984 Darwinia 25:43--57
Munroa squarrosa (Nutt.) Torr.
Habit: Plant mat-like, generally < 20 cm wide. Stem: 3--15(30) cm, slender, many-branched, scabrous, often minutely puberulent. Leaf: ligule 0.5(1) mm; blade 1--5 cm, 1--2.5 mm wide. Spikelet: 6--8(10) mm, florets 3--5; glumes of lower 1--2 spikelets subequal, 2.5--4.2 mm, narrow, 1-veined, acute; glumes of upper spikelets unequal, lower reduced or 0 in terminal spikelet; lemma scabrous, lanceolate, lateral veins hairy-tufted near middle, tip awned, awn 0.5--2 mm, stout, scabrous; anthers 1--1.5 mm. Chromosomes: 2n=16.
Ecology: Open, sandy, gravelly or rocky places; Elevation: 1500--1800 m. Bioregional Distribution: DMtns (Clark Mtn Range); Distribution Outside California: to Great Plains, Texas, northern Mexico. Flowering Time: Aug--Oct
Jepson eFlora Author: Jesús Valdés-Reyna
Reference: Valdés-Reyna 2003 FNANM 25:51--52
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)
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Botanical illustration including Munroa squarrosa

botanical illustration including Munroa squarrosa


Citation for this treatment: Jesús Valdés-Reyna 2012, Munroa squarrosa, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on December 14, 2019.

Citation for the whole project: Jepson Flora Project (eds.) 2019, Jepson eFlora,, accessed on December 14, 2019.

Munroa squarrosa
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© 2011 Steve Matson
Munroa squarrosa
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© 2012 Keir Morse
Munroa squarrosa
click for enlargement
© 2012 Keir Morse
Munroa squarrosa
click for enlargement
© 2011 Steve Matson
Munroa squarrosa
click for enlargement
© 2012 Keir Morse
Munroa squarrosa
click for enlargement
© 2009 James M. Andre

More photos of Munroa squarrosa in CalPhotos

Geographic subdivisions for Munroa squarrosa:
DMtns (Clark Mtn Range)
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map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).


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Data provided by the participants of the  Consortium of California Herbaria.
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All markers link to CCH specimen records. The original determination is shown in the popup window.
Blue markers indicate specimens that map to one of the expected Jepson geographic subdivisions (see left map). Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
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CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa, if there are more than 1 infraspecific taxon in CA.
Blue line denotes eFlora flowering time.