Jepson eFlora: Taxon page
Key to families | Table of families and genera
Previous taxon Index to accepted names and synonyms:
| A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
Next taxon
Aristida
THREE-AWN

Higher Taxonomy
Family: Poaceae (Gramineae)View DescriptionDichotomous Key

Common Name: GRASS FAMILY
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.

Aristida
Habit: Annual, perennial herb, cespitose. Stem: ascending to erect, generally glabrous (except Aristida californica). Leaf: basal and cauline; basal often tufted; ligule hairy; blade flat or inrolled. Inflorescence: raceme-like or panicle-like; branches spike-like. Spikelet: glumes narrowly lanceolate, thin, 1-veined, awn generally 0; floret 1, breaking above glumes; lemma +- fusiform, hard when mature, 3-veined, tip beak-like or not, awned at tip, awns 3, equal or unequal; palea < lemma, enclosed by lemma, transparent. Fruit: narrowly fusiform.
Species In Genus: +- 300 species: worldwide, arid warm temperate. Etymology: (Latin: awn) Note: Some species noxious weeds.
eFlora Treatment Author: Rosa Cerros-Tlatilpa & Kelly W. Allred
Jepson Online Interchange
Key to Aristida

Previous taxon: Apera spica-venti
Next taxon: Aristida adscensionis

Name Search

Contact/Feedback

Citation for this treatment: Rosa Cerros-Tlatilpa & Kelly W. Allred 2016. Aristida, in Jepson Flora Project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/cgi-bin/get_IJM.pl?tid=10984, accessed on December 04, 2016.

Citation for the whole project: Jepson Flora Project (eds.) 2016. Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html, accessed on December 04, 2016.


Aristida purpurea var. nealleyi
click for enlargement
© 2015 Steve Matson
Aristida purpurea var. nealleyi
click for enlargement
© 2013 Steve Matson
Aristida californica
click for enlargement
© 2012 Keir Morse
Aristida oligantha
click for enlargement
© 2013 Steve Matson
Aristida purpurea var. fendleriana
click for enlargement
© 2013 Steve Matson
Aristida purpurea var. nealleyi
click for enlargement
© 2013 Steve Matson

More photos of Aristida in CalPhotos