The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Chinese caps, western wood spurge

coastal dune sandmat

Habit Herbs, usually biennial, occasionally annual, with taproot. Herbs, usually annual, rarely perennial, with taproot.
Stems

erect, sometimes decumbent at base, unbranched or branched, 12–40 cm, glabrous.

prostrate, 10–20 cm, glabrous.

Leaves

petiole 0–2 mm;

blade obovate-spatulate to oblanceolate, 8–22 × 3–10 mm, base broadly attenuate, margins entire or slightly crisped, apex obtuse to ± rounded, minutely apiculate, surfaces glabrous;

venation pinnate, midvein prominent.

opposite;

stipules distinct, linear-subulate, usually divided into 3–7 linear segments, 0.5–1 mm, glabrous;

petiole 0.5–1 mm, glabrous;

blade narrowly elliptic to lanceolate, 4–8 × 1–2 mm uniform in size, base asymmetric, obtuse to rounded, margins entire, apex obtuse to acute, surfaces green to reddish flushed, glabrous;

only midvein conspicuous.

Involucre

campanulate, 1.8–2.1 × 1.6–1.8 mm, glabrous;

glands 4, crescent-shaped, 0.6–1.2 × 1.5–2.3 mm;

horns slightly divergent to slightly convergent, 0.4–0.6 mm.

campanulate, 0.9–1.1 × 1–1.3 mm, glabrous;

glands 4, green to red, slightly stipitate, subcircular, 0.1 × 0.1 mm;

appendages white or pink, fringing edge of gland, short-flabellate, often rudimentary, 0.1–0.2 × 0.1 mm, distal margin crenate or entire.

Staminate flowers

11–18.

5–8.

Pistillate flowers

ovary glabrous;

styles 0.9–1.4 mm, 2-fid.

ovary glabrous;

styles 0.2–0.3 mm, 2-fid at apex to nearly 1/2 length.

Capsules

subovoid, 2.5–3 × 3.5–4 mm, 3-lobed;

cocci rounded, smooth or puncticulate, glabrous;

columella 1.9–2.3 mm.

ovoid or subglobose, 1.8–2 × 2–2.3 mm, glabrous;

columella 1.2–1.5 mm.

Seeds

cream and brown mottled, oblong-ovoid to nearly globose, 2–2.5 × 1.4–1.7 mm, usually irregularly vermiculate-ridged and large-pitted, occasionally tuberculate or nearly smooth;

caruncle reniform, conic, 0.5–0.6 × 0.5–0.7 mm.

white to gray-brown, ovoid, terete to bluntly subangled in cross section, 1–1.3 × 1 mm, smooth or minutely pitted, with smooth brown line from top to bottom on adaxial side.

Cyathial

arrangement: terminal pleiochasial branches 3, each 2-branched;

pleiochasial bracts obovate to orbiculate-reniform, wider than distal leaves;

dichasial bracts usually connate 1/3–1/2 length (often only on one side), rarely only connate basally, triangular ovate to reniform, base truncate to perfoliate, margins erose-denticulate to subentire, apex rounded to obtuse, rarely apiculate;

axillary cymose branches 0–5.

Cyathia

peduncle 0–0.5 mm.

solitary at distal nodes;

peduncle 1 mm.

Euphorbia crenulata

Euphorbia cumulicola

Phenology Flowering and fruiting spring–summer. Flowering and fruiting year-round.
Habitat Conifer, oak, and mixed forests, coastal scrub, grasslands, barrens and outcrops, roadsides. Sandy oak hammocks, open sandy areas behind mangroves, disturbed sandy sites.
Elevation 30–1800 m. (100–5900 ft.) 0–10 m. (0–0 ft.)
Distribution
from FNA
CA; CO; NM; OR
[WildflowerSearch map]
[BONAP county map]
from FNA
FL
[BONAP county map]
Discussion

Euphorbia crenulata is most common in the central valleys of California and southern Oregon; it occurs disjunctly in southwestern Colorado and northwestern New Mexico. Previous reports from Arizona are based on misidentified specimens. Euphorbia crenulata is closely related to E. commutata.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Euphorbia cumulicola could be confused with E. bombensis, both of which are widespread in Florida, but there the latter occurs on beaches close to the ocean, whereas E. cumulicola is not a beach-inhabiting species but occurs in more protected sandy habitats such as hammocks or stabilized dunes behind mangroves. Also, E. bombensis has fleshier leaves and larger seeds, and is more compact in habit than E. cumulicola, which is a more sprawling and densely branched plant with leaves that are usually purplish tinged along the margins.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 12, p. 301. FNA vol. 12, p. 265.
Parent taxa Euphorbiaceae > Euphorbia > subg. Esula Euphorbiaceae > Euphorbia > sect. Anisophyllum
Sibling taxa
E. aaron-rossii, E. abramsiana, E. acuta, E. agraria, E. albomarginata, E. alta, E. angusta, E. antisyphilitica, E. arizonica, E. astyla, E. austrotexana, E. bicolor, E. bifurcata, E. bilobata, E. blodgettii, E. bombensis, E. brachycera, E. capitellata, E. carunculata, E. chaetocalyx, E. chamaesula, E. cinerascens, E. commutata, E. conferta, E. cordifolia, E. corollata, E. cumulicola, E. cuphosperma, E. curtisii, E. cyathophora, E. cyparissias, E. davidii, E. deltoidea, E. dendroides, E. dentata, E. discoidalis, E. eriantha, E. exigua, E. exserta, E. exstipulata, E. falcata, E. fendleri, E. florida, E. floridana, E. garberi, E. georgiana, E. geyeri, E. glyptosperma, E. golondrina, E. gracillima, E. graminea, E. helioscopia, E. helleri, E. heterophylla, E. hexagona, E. hirta, E. hooveri, E. humistrata, E. hypericifolia, E. hyssopifolia, E. indivisa, E. innocua, E. inundata, E. ipecacuanhae, E. jaegeri, E. jejuna, E. laredana, E. lasiocarpa, E. lata, E. lathyris, E. longicruris, E. lurida, E. macropus, E. maculata, E. marginata, E. meganaesos, E. melanadenia, E. mendezii, E. mercurialina, E. mesembrianthemifolia, E. micromera, E. misera, E. missurica, E. myrsinites, E. nephradenia, E. nutans, E. oblongata, E. ocellata, E. ophthalmica, E. ouachitana, E. parishii, E. parryi, E. pediculifera, E. peplidion, E. peplus, E. perennans, E. pergamena, E. pinetorum, E. platyphyllos, E. platysperma, E. polycarpa, E. polygonifolia, E. polyphylla, E. porteriana, E. prostrata, E. pubentissima, E. purpurea, E. radians, E. rayturneri, E. revoluta, E. roemeriana, E. rosescens, E. schizoloba, E. serpens, E. serpillifolia, E. serrata, E. serrula, E. setiloba, E. simulans, E. spathulata, E. stictospora, E. strictior, E. telephioides, E. terracina, E. tetrapora, E. texana, E. theriaca, E. thymifolia, E. tithymaloides, E. trachysperma, E. trichotoma, E. vallis-mortae, E. velleriflora, E. vermiculata, E. villifera, E. virgata, E. wrightii, E. yaquiana
E. aaron-rossii, E. abramsiana, E. acuta, E. agraria, E. albomarginata, E. alta, E. angusta, E. antisyphilitica, E. arizonica, E. astyla, E. austrotexana, E. bicolor, E. bifurcata, E. bilobata, E. blodgettii, E. bombensis, E. brachycera, E. capitellata, E. carunculata, E. chaetocalyx, E. chamaesula, E. cinerascens, E. commutata, E. conferta, E. cordifolia, E. corollata, E. crenulata, E. cuphosperma, E. curtisii, E. cyathophora, E. cyparissias, E. davidii, E. deltoidea, E. dendroides, E. dentata, E. discoidalis, E. eriantha, E. exigua, E. exserta, E. exstipulata, E. falcata, E. fendleri, E. florida, E. floridana, E. garberi, E. georgiana, E. geyeri, E. glyptosperma, E. golondrina, E. gracillima, E. graminea, E. helioscopia, E. helleri, E. heterophylla, E. hexagona, E. hirta, E. hooveri, E. humistrata, E. hypericifolia, E. hyssopifolia, E. indivisa, E. innocua, E. inundata, E. ipecacuanhae, E. jaegeri, E. jejuna, E. laredana, E. lasiocarpa, E. lata, E. lathyris, E. longicruris, E. lurida, E. macropus, E. maculata, E. marginata, E. meganaesos, E. melanadenia, E. mendezii, E. mercurialina, E. mesembrianthemifolia, E. micromera, E. misera, E. missurica, E. myrsinites, E. nephradenia, E. nutans, E. oblongata, E. ocellata, E. ophthalmica, E. ouachitana, E. parishii, E. parryi, E. pediculifera, E. peplidion, E. peplus, E. perennans, E. pergamena, E. pinetorum, E. platyphyllos, E. platysperma, E. polycarpa, E. polygonifolia, E. polyphylla, E. porteriana, E. prostrata, E. pubentissima, E. purpurea, E. radians, E. rayturneri, E. revoluta, E. roemeriana, E. rosescens, E. schizoloba, E. serpens, E. serpillifolia, E. serrata, E. serrula, E. setiloba, E. simulans, E. spathulata, E. stictospora, E. strictior, E. telephioides, E. terracina, E. tetrapora, E. texana, E. theriaca, E. thymifolia, E. tithymaloides, E. trachysperma, E. trichotoma, E. vallis-mortae, E. velleriflora, E. vermiculata, E. villifera, E. virgata, E. wrightii, E. yaquiana
Synonyms Tithymalus crenulatus Chamaesyce cumulicola
Name authority Engelmann: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 192. (1859) (Small) Oudejans: Phytologia 67: 45. (1989)
Web links