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Vascular Plants of California
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Tridens muticus var. muticus

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: TridensView Description 

Habit: Perennial herb, generally cespitose, often rhizomatous. Stem: generally erect, 5--180 cm. Leaf: ligule fringed or short-hairy; blade flat or inrolled, margins not thickened. Inflorescence: terminal, generally panicle-like, open to dense, or spike-like. Spikelet: laterally compressed; glumes +- equal, membranous, lower 1(3)-veined, upper 1--3(9)-veined; axis breaking above glumes and between florets; florets generally 4--11; lemma wide, thin, back rounded, veins hairy below middle, 3-veined, tip notched or 2-toothed, generally short-pointed; palea generally < lemma, glabrous or minutely hairy below; anthers 3, red-purple.
Etymology: (Latin: 3 tooth, from 3-veined lemma tip in type sp.)
eFlora Treatment Author: James P. Smith, Jr.
Reference: Valdés-Reyna 2003 FNANM 25:33--40
Unabridged Reference: Tateoka 1961 Amer J Bot 48:565--573
Tridens muticus (Torr.) Nash var. muticus
Habit: Plant tufted, shortly rhizomatous. Stem: generally 20--50 cm. Leaf: sheath hairy, especially near collar; ligule short-hairy; blade 3--25 cm, 1--4 mm wide, generally inrolled, +- fine scabrous, sometimes sparsely hairy. Inflorescence: 4--20 cm, 3--8 mm wide, narrow; branches short, appressed; spikelets subsessile to short-stalked. Spikelet: 8--13 mm, +- cylindric; glumes 3--10 mm, lower 1--3-veined, upper glume 1-veined; florets 5--11, strongly overlapping, pale to light purple; callus densely hairy; lemma 3--7 mm, generally purple-tinged, veins densely hairy below middle, tip entire to minutely notched; palea margins hairy, < lemma. Chromosomes: 2n=40.
Ecology: Dry, rocky, generally limestone soils, creosote-bush scrub, pinyon/juniper woodland; Elevation: < 2000 m. Bioregional Distribution: ne PR, D; Distribution Outside California: southwestern and south-central United States, northern Mexico. Flowering Time: Apr--May, Oct--Nov
Jepson eFlora Author: James P. Smith, Jr.
Reference: Valdés-Reyna 2003 FNANM 25:33--40
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)

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Botanical illustration including Tridens muticus var. muticus

botanical illustration including Tridens muticus var. muticus

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Citation for this treatment: James P. Smith, Jr. 2012, Tridens muticus var. muticus, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on April 12, 2024.

Citation for the whole project: Jepson Flora Project (eds.) 2024, Jepson eFlora,, accessed on April 12, 2024.

Tridens muticus  
var. muticus
click for enlargement
©2016 Keir Morse
Tridens muticus  
var. muticus
click for enlargement
©2016 Keir Morse
Tridens muticus  
var. muticus
click for enlargement
©2016 Keir Morse
Tridens muticus  
var. muticus
click for enlargement
©2016 Keir Morse
Tridens muticus  
var. muticus
click for enlargement
©2016 Keir Morse

More photos of Tridens muticus var. muticus
in CalPhotos

Geographic subdivisions for Tridens muticus var. muticus:
ne PR, D
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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).


Data provided by the participants of the  Consortium of California Herbaria.
View all CCH records
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.
Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.

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 (fruiting time in some monocot genera).