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Vascular Plants of California
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Hilaria rigida


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: HilariaView DescriptionDichotomous Key

Habit: Perennial herb, cespitose, rhizomed. Stem: ascending to erect, solid; nodes generally hairy. Leaf: ligule membranous, ciliate-fringed; blade firm, flat to inrolled, sharply acute. Inflorescence: spike-like, generally cylindric; spikelets in clusters, 3 per node, +- equal; clusters wedge-shaped, overlapping, ascending to appressed, hairy-tufted at base, falling as 1 unit from zigzag axis; glumes of cluster together involucre-like. Central Spikelet: subsessile, appressed to or nearest inflorescence axis; glumes equal, < floret(s), oblanceolate, keeled, ciliate, tip deeply 2-lobed, lobes lanceolate, awns 3--9, 1 from +- mid-keel, others terminal; florets generally 1--2, lower floret bisexual, upper floret (if present) bisexual or staminate; lemma lanceolate, 3-veined, generally ciliate, tip generally 2-lobed, generally 1-awned +- from sinus; palea +- = lemma.Lateral Spikelet: sessile; glumes < to +- = florets, ciliate, lower glume asymmetric with 1 awn from +- middle near margin, generally 2-lobed, lobes unequal; florets 1--4, generally staminate; lemma 3-veined, tip generally ciliate; palea +- = lemma.
Etymology: (Auguste de Saint-Hilaire, French biologist, 1779--1853)
eFlora Treatment Author: J. Travis Columbus
Unabridged Reference: Reeder & Reeder 1988 Madroño 35:6--9
Hilaria rigida (Thurb.) Benth. ex Scribn.
Habit: Plant 3.5--10 dm, branched above base, generally bush-like. Stem: 1.5--3.5 mm diam at base; node hairs curly. Leaf: generally cauline, generally sparsely to densely tomentose, especially near and sometimes overlapping ligule; ligule membrane < 1 mm, lateral teeth 0; blade < 10 cm, 2--4 mm wide. Inflorescence: 4--10 cm; spikelet clusters 7--11 mm. Central Spikelet: glume margin hairs 0.5--3 mm; lower lemma tip sometimes 4-lobed, awns 3, +- from sinuses, central awn 2--5.5 mm. Lateral Spikelet: lower glume with 1+ subsidiary lobes, or larger lobe tip fringed, awns 2--4; upper glume tip with 2+ lobes or fringed, awns 1--3, 0.4--2.5 mm, margin hairs 0.5--2 mm; lemma tip 2-lobed, awn 1 +- from sinus, 0.4--2 mm, margin hairs 0.2--1 mm. Chromosomes: 2n=18,36,+-108.
Ecology: Common. Dry, open, sandy to rocky slopes, flats, and washes, sand dunes, scrub, woodland; Elevation: < 1600 m. Bioregional Distribution: PR, e&s DMoj, DSon; Distribution Outside California: to Utah, northwestern Mexico. Flowering Time: All year Note: Important forage; some plants from eastern DMoj and Ord Mtn (San Bernardino Co.), with +- straight internode hairs, intermediate to Hilaria jamesii.
Synonyms: Pleuraphis rigida Thurb.
Jepson eFlora Author: J. Travis Columbus
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)

Previous taxon: Hilaria jamesii
Next taxon: Holcus

Botanical illustration including Hilaria rigidabotanical illustration including Hilaria rigida

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Citation for this treatment: J. Travis Columbus 2012, Hilaria rigida, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on July 14, 2024.

Citation for the whole project: Jepson Flora Project (eds.) 2024, Jepson eFlora,, accessed on July 14, 2024.

Hilaria rigida
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©2008 Steve Matson
Hilaria rigida
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©2004 James M. Andre
Hilaria rigida
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©2011 Steve Matson
Hilaria rigida
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©2015 Keir Morse
Hilaria rigida
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©2009 Keir Morse

More photos of Hilaria rigida
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Geographic subdivisions for Hilaria rigida:
PR, e&s DMoj, DSon
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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 occurrence).


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 Flowering-Fruiting Monthly Counts

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).