Editor(s):
J.A. Peirson and Ya Yang


  Name:      Euphorbia dentata   Michx., Fl. Bor.-Amer. 2: 211. 1803.

Status:accepted_name
Accepted Name:None
Basionym:None
Common Names:
Toothed Spurge
TOLKIN GUID:b980cdf7-70b8-43e9-83a9-a1caf4449c50
TOLKIN GUID URL:http://app.tolkin.org/guids/b980cdf7-70b8-43e9-83a9-a1caf4449c50
Type Details:
Species: None
Type Collection:
Michaux s.n.
Type Date: None
Type Locality:
U.S.A.: Tennessee, “juxta Nashville,” ca. Aug-Sep 1802
Type Herbaria:
Holotype: P-Mich
Neo Type: None
Synonyms: show/hide
Name
Namestatus
Anisophyllum dentatum (Michx.) Haw., Syn. Pl. Succ. 162. 1812.
Synonym
Euphorbia cruentata Graham, Edinburgh New Philos. J. 13: 361. 1832 [Oct.].
Synonym
Euphorbia herronii Riddell, Syn. Fl. West. States 32. 1835.
Synonym
Euphorbia fontanesii Steud., Nomencl. Bot. , ed. 2, 1: 611. 1840.
Synonym
Euphorbia dentata var. rigida Engelm., Rep. U.S. Mex. Bound. 2(1): 190. 1859.
Synonym
Poinsettia dentata (Michx.) Klotzsch & Garcke, Monatsber. Königl. Preuss. Akad. Wiss. Berlin 1859: 253. 1859.
Synonym
Euphorbia dentata var. linearis Engelm. ex Boiss., Prodr. 15(2): 72. 1862.
Synonym
Euphorbia dentata f. cuphosperma (Engelm.) Fernald, Rhodora 50: 148. 1948.
Synonym
Euphorbia purpureomaculata T.J. Feng & J.X. Huang, Bull. Bot. Res., Harbin 13: 65. 1993.
Synonym
Subgenus:
Chamaesyce
Section:
Poinsettia
Subsection:
Stormieae
Ingroup Clade:
D
Description:
Adapted from Flora of North America, treatment by Jess A. Peirson (description and habitat information based on U.S.A. collections only):

Annual herbs, from a taproot. Stems erect or ascending, branched, pilose (outer layer) and inconspicuously strigulose (inner layer), 15-60 cm. Leaves opposite (occasionally alternate at distal nodes); bracteate leaves few, loosely subtending the inflorescence, similar in size and shape to distal stem leaves, green with paler green, white, or mauve coloration at the base; stipules absent or minute, glanduliform; petiole 5--20 mm, pilose; blade 30--70 x 4--35 mm, narrowly lanceolate to suborbicular, usually broadest below the middle, penninerved, midvein prominent, sparsely pilose to subglabrous adaxially, long pilose abaxially with weak, filiform trichomes, base acute to subobtuse, rarely subtruncate, apex bluntly acute, margin coarsely crenate-dentate (or doubly crenate), strigulose, flat to slightly revolute. Cyathia 5--40 per inflorescence; peduncle 0.7--1 mm. Involucre campanulate, 3.8 x 1.8 mm, glabrous; involucral lobes divided into several linear, smooth lobes; glands two (occasionally solitary), sessile and broadly attached, 0.7--0.9 x 0.9--1.2 mm, opening oblong, green. Staminate flowers 8--10. Pistillate flower: ovary glabrous, style 1.2 mm, divided to the base. Capsule depressed-spheroid, 3-lobed, 2.5--2.8 x 3.5--4 mm, glabrous, columella 1.8--2.1 mm. Seeds ovoid, 2.1--2.7 x 1.7--2.1 mm wide, pale gray to black, evenly minute-tuberculate; caruncle 0.4--0.6 mm.
Habitat:
Flowering and fruiting spring and fall.

Bottomland forests, stream and river banks, bluffs, prairies and glades, and also fallow fields, roadsides, railroad cinders, and open disturbed areas. 0--1000 m.
Phylogenetic Relationships: None
Comments:
This species is native to northern Mexico and the south central United States north and east through the Ohio Valley. In Mexico this species occurs in the mountains of northern Tamaulipas, Nuevo Leon and Coahuila, with a disjunct location in southeastern Chihuahua.

It is unclear whether scattered occurrences in the southeastern United States represent native or adventive populations. Reports of Euphorbia dentata as a noxious weed (from the United States and also the Old World) should most likely be attributed to introductions of Euphorbia davidii.
Chromosome Number:
2n = 28.
Uses: None
Toxicity: None
Conservation Status: None
General Distribution:
U.S.A. (Colorado, Wyoming, Illinois, Iowa, Kansas, Minnesota, Missouri, Nebraska, Oklahoma, South Dakota, Wisconsin, Indiana, Michigan, Maryland, Ohio, Pennsylvania, West Virginia, Arizona, California, Utah, New Mexico, Texas, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Virginia), Mexico to Central America (Guatemala, Honduras)
Collector
Collection number
Country
Institution code
Carrillo-Reyes, P.
2353
Mexico
GUADA
Carrillo-Reyes, P.
5601a
Mexico
Carrillo-Reyes, P.
900
Mexico
IBUG
Riddell
s.n.
United States
PH
Engelmann
s.n.
U.S.A.
G fiche
Engelmann
s.n.
U.S.A.
MO
Michaux
s.n.
U.S.A.
P
Van Devender, T.R.
2006-340
U.S.A.
MICH
Wright
1837
U.S.A.
MO, F
Wright
1837
U.S.A.
G fiche, GH
DNA Sample(s): 6470
DNA Sample(s) Sequences
References:

Berry, P.E., Peirson, J., Steinmann, V.W., Morawetz, J.J., Riina, R., Yang, Y., Geltman, D.V., and Cacho, N.I. (in review). "Euphorbia." In: Flora of North America north of Mexico 12, Flora of North America Editorial Committee. New York and Oxford.

Mayfield, M.H. (1997). A systematic treatment of Eupborbia subgenus Poinsettia (Eupborbiaceae). Ph.D. dissertation, The University of Texas at Austin, Austin, Texas, U.S.A.

Ward, D.E. (1983). Chromosome counts from New Mexico and southern Colorado. Phytologia 54, 302-309.

Yang, Y., Riina, R., Morawetz, J.J., Steinmann, V.W., Haevermans, T., Aubriot, X., and Berry, P.E. (2012). Molecular phylogenetics and classification of Euphorbia subgenus Chamaesyce (Euphorbiaceae). Taxon 61(4), 764-789.


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