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

coast clover, cow clover, cows clover, salt marsh clover, springbank clover, wormskjold's clover

woolly-head clover

Habit Herbs perennial, 10–40 cm, glabrous; rhizomes elongate. Herbs perennial, 12–46 cm, sparsely hairy to densely villous, appressed-pubescent, or glabrate.
Stems

erect, ascending, or decumbent, branched.

erect or decumbent, branched.

Leaves

palmate;

stipules ovate to lanceolate, 1.5–2 cm, margins entire (proximal stipules) or lacerate (distal stipules), apex acute to acuminate;

petiole 1–11 cm;

petiolules 0.5 mm;

leaflets 3, blades obovate to elliptic, 0.4–4.2 × 0.2–1.3 cm, base cuneate or rounded, veins fine or thickened distally, margins spinulose-serrate, apex usually acute to rounded, sometimes retuse or mucronate, surfaces glabrous.

palmate;

stipules lanceolate or ovate, 1–5 cm, margins entire or denticulate, apex acuminate or acute;

petiole 1–15 cm;

petiolules 1 mm;

leaflets 3, blades linear, linear-elliptic, elliptic, lanceolate, lanceolate-oblong, or obovate, 1–5 × 0.4–1.2 cm, base cuneate, veins fine or ± thickened, margins denticulate or serrulate, apex acuminate or acute, surfaces appressed-pubescent abaxially, glabrous, densely villous, or sparsely or densely pilose adaxially.

Inflorescences

axillary or terminal, 20–50-flowered, subglobose or globose, 1.8–2.5 × 2–2.5 cm;

involucres broadly bowl-shaped, 12–20 mm, incised 1/3–1/2 their length, lobes 10+, sharply and acutely serrate, veins prominent.

terminal or axillary, 25–70-flowered, inverted or horizontal, ellipsoid or globose to subglobose, 2–3 × 1–3 cm, rachis prolonged beyond flowers;

involucres absent.

Peduncles

1.5–11 cm.

bent distally, proximal to flowers, 3–18 cm.

Pedicels

straight, 1.5–2 mm;

bracteoles linear or ovate, 1–2 mm.

reflexed, to 0.3 mm;

bracteoles absent.

Flowers

12–14 mm, odor somewhat unpleasant;

calyx whitish, tubular, 5–6 mm, glabrous, veins 10, tube 2–3 mm, lobes green to purple, subequal, abaxial rarely longer than tube, orifice open;

corolla usually magenta to purple, rarely white or bicolored, 10–12 mm, banner ovate-oblong, 12–14 × 2–3 mm, apex truncate or rounded, slightly retuse.

9–18 mm;

calyx campanulate, curved in fruit, 4–11 mm, villous, veins 10, tube 1.5–2.5 mm, lobes unequal, 2–3 times tube, subulate, often strongly curved and twisted, plumose, orifice open;

corolla white, cream, or purple, 8–16 mm, banner oblanceolate, 8–16 × 3–5 mm, apex rounded or retuse, recurved;

ovaries pubescent distally.

Legumes

oblong, 2–4 mm.

ovoid, 2–3.5 mm.

Seeds

3 or 4, brown, sometimes mottled, subglobose or mitten-shaped, 1.5 mm, smooth.

(1 or)2–4, yellow-brown to brown, mitten-shaped or subglobose, 1.2–2 mm, smooth.

2n

= 16, 32.

Trifolium wormskioldii

Trifolium eriocephalum

Phenology Flowering Mar–Sep.
Habitat Saline flats, beaches, meadows, grassy areas, alluvial soils.
Elevation 0–2700 m. (0–8900 ft.)
Distribution
from FNA
AZ; CA; CO; ID; NM; NV; OR; UT; WA; WY; BC; Mexico (Baja California)
[WildflowerSearch map]
[BONAP county map]
from USDA
w United States
[WildflowerSearch map]
[BONAP county map]
Discussion

Trifolium wormskioldii is largely tetraploid and is widespread in western North America. Distinguishing T. wormskioldii from closely allied species (especially T. mucronatum) is sometimes difficult, which led R. C. Barneby (1989) to synonymize T. mucronatum and T. pinetorum under the former name. Trifolium wormskioldii produces long, white rhizomes; T. mucronatum produces only short rhizomes at most, often only small, fibrous roots or taproots (J. M. Gillett 1980). The distinction of T. pinetorum from T. wormskioldii was supported by N. W. Ellison et al. (2006); those authors did not include material of T. mucronatum in their DNA analyses.

Trifolium wormskioldii rhizomes may have been a food resource for Native American groups in the Pacific Northwest (N. J. Turner and H. V. Kuhnlein 1982).

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

Subspecies 6 (6 in the flora).

Trifolium eriocephalum was revised by J. M. Gillett (1971). The subspecies exhibit unusually complex distributional patterns, and overlapping morphological features sometimes make identifications problematic (M. Zohary and D. Heller 1984).

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

Key
1. Ovules usually 2, rarely 1 or 3; calyx lobes usually green, rarely purple, straight, subequal, 3–4 timestube.
→ 2
2. Herbs densely villous; leaflet blades of basal and median leaves elliptic or lanceolate-oblong; roots cylindric, thickened.
subsp. eriocephalum
2. Herbs slightly villous, appressed-pubescent, or glabrate; leaflet blades of basal and med­ian leaves usually narrowly lanceolate or lin­ear, rarely narrowly elliptic; roots fusiform-tuberous.
subsp. cascadense
1. Ovules 3 or 4; calyx lobes usually purple, contorted, abaxial lobes longer, lateral lobes 1–1.5 times tube.
→ 3
3. Leaflet blades of basal leaves linear or linear-elliptic, apex acute, surfaces sparsely or densely hairy adaxially; roots cylindric, thickened, branched, often rhizomelike.
→ 4
4. Blades of leaflets of median leaves linear or linear-elliptic; herbs slightly villous.
subsp. cusickii
4. Blades of leaflets of median leaves broadly elliptic; herbs densely villous.
subsp. villiferum
3. Leaflet blades of basal leaves obovate, apex rounded to retuse, surfaces usually glabrous adaxially, sometimes sparsely hairy; roots fusiform-tuberous.
→ 5
5. Inflorescences 2.5 cm diam., significantly overtopping distal leaves; leaflet blades of median leaves broadly lanceolate, surfaces sparsely hairy or glabrous adaxially.
subsp. arcuatum
5. Inflorescences 1 cm diam., scarcely over­topping distal leaves; leaflet blades of median leaves narrowly lanceolate or linear, surfaces densely villous adaxially.
subsp. martinii
Source FNA vol. 11. FNA vol. 11.
Parent taxa Fabaceae > subfam. Faboideae > Trifolium Fabaceae > subfam. Faboideae > Trifolium
Sibling taxa
T. albopurpureum, T. alexandrinum, T. amoenum, T. amphianthum, T. andersonii, T. andinum, T. angustifolium, T. appendiculatum, T. arvense, T. attenuatum, T. aureum, T. barbigerum, T. barnebyi, T. beckwithii, T. bejariense, T. bifidum, T. bolanderi, T. brandegeei, T. breweri, T. buckwestiorum, T. calcaricum, T. campestre, T. carolinianum, T. cernuum, T. ciliolatum, T. columbinum, T. cyathiferum, T. dasyphyllum, T. dedeckerae, T. depauperatum, T. dichotomum, T. douglasii, T. dubium, T. echinatum, T. eriocephalum, T. fragiferum, T. friscanum, T. fucatum, T. glomeratum, T. gracilentum, T. grayi, T. gymnocarpon, T. haydenii, T. hirtum, T. howellii, T. hybridum, T. hydrophilum, T. incarnatum, T. jokerstii, T. kentuckiense, T. kingii, T. lappaceum, T. latifolium, T. leibergii, T. lemmonii, T. longipes, T. lupinaster, T. macilentum, T. macraei, T. macrocephalum, T. medium, T. microcephalum, T. microdon, T. monanthum, T. mucronatum, T. nanum, T. nigrescens, T. obtusiflorum, T. oliganthum, T. ornithopodioides, T. owyheense, T. palmeri, T. parryi, T. pinetorum, T. piorkowskii, T. plumosum, T. polyodon, T. pratense, T. productum, T. reflexum, T. repens, T. resupinatum, T. retusum, T. rollinsii, T. siskiyouense, T. sonorense, T. stoloniferum, T. striatum, T. subterraneum, T. suffocatum, T. thompsonii, T. tomentosum, T. trichocalyx, T. variegatum, T. vesiculosum, T. virginicum, T. willdenovii
T. albopurpureum, T. alexandrinum, T. amoenum, T. amphianthum, T. andersonii, T. andinum, T. angustifolium, T. appendiculatum, T. arvense, T. attenuatum, T. aureum, T. barbigerum, T. barnebyi, T. beckwithii, T. bejariense, T. bifidum, T. bolanderi, T. brandegeei, T. breweri, T. buckwestiorum, T. calcaricum, T. campestre, T. carolinianum, T. cernuum, T. ciliolatum, T. columbinum, T. cyathiferum, T. dasyphyllum, T. dedeckerae, T. depauperatum, T. dichotomum, T. douglasii, T. dubium, T. echinatum, T. fragiferum, T. friscanum, T. fucatum, T. glomeratum, T. gracilentum, T. grayi, T. gymnocarpon, T. haydenii, T. hirtum, T. howellii, T. hybridum, T. hydrophilum, T. incarnatum, T. jokerstii, T. kentuckiense, T. kingii, T. lappaceum, T. latifolium, T. leibergii, T. lemmonii, T. longipes, T. lupinaster, T. macilentum, T. macraei, T. macrocephalum, T. medium, T. microcephalum, T. microdon, T. monanthum, T. mucronatum, T. nanum, T. nigrescens, T. obtusiflorum, T. oliganthum, T. ornithopodioides, T. owyheense, T. palmeri, T. parryi, T. pinetorum, T. piorkowskii, T. plumosum, T. polyodon, T. pratense, T. productum, T. reflexum, T. repens, T. resupinatum, T. retusum, T. rollinsii, T. siskiyouense, T. sonorense, T. stoloniferum, T. striatum, T. subterraneum, T. suffocatum, T. thompsonii, T. tomentosum, T. trichocalyx, T. variegatum, T. vesiculosum, T. virginicum, T. willdenovii, T. wormskioldii
Subordinate taxa
T. eriocephalum subsp. arcuatum, T. eriocephalum subsp. cascadense, T. eriocephalum subsp. cusickii, T. eriocephalum subsp. eriocephalum, T. eriocephalum subsp. martinii, T. eriocephalum subsp. villiferum
Synonyms Lupinaster wormskioldii, T. fendleri, T. fimbriatum, T. heterodon, T. spinulosum
Name authority Lehmann: Index Seminum (Hamburg) 1825: 17. (1825) Nuttall in J. Torrey and A. Gray: Fl. N. Amer. 1: 313. (1838)
Web links