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Alsike clover

marshmallow clover, Piorkowski's clover

Habit Herbs perennial, 10–70 cm, glabrous or sparsely hairy. Herbs annual, 7–30 cm, glabrous.
Stems

erect or ascending, branched.

erect or ascending, sparsely to much branched.

Leaves

palmate;

stipules obovate or lanceolate, 1–2.5 cm, margins entire or toothed, apex long-acuminate;

petiole 1–21 cm;

petiolules 1 mm;

leaflets 3, blades usually obovate or ovate, rarely rhombic, 1–4 × 1–2.5 cm, base cuneate, veins prominent, margins sharply serrate, apex broadly acute, obtuse, or emarginate, surfaces glabrous.

palmate;

stipules ovate-lanceolate, 1–1.5 cm, margins entire, apex acute-acuminate;

petiole 8–12 cm;

petiolules 1 mm;

leaflets 3, blades oblanceolate or obovate, 2.8 × 1.9 cm, base cuneate, veins delicate, margins entire or shallowly dentate distally, lateral veins sometimes ending in a bristle, apex rounded to acute, surfaces glabrous.

Inflorescences

terminal or axillary, 10–70+-flowered, globose to subglobose, 1–2.5 × 1–2.5 cm, rachis not prolonged beyond flowers;

involucres absent.

axillary or terminal, 3–16-flowered, in 1–3 whorls, subglobose, 2–2.8 × 1.8–2.6 cm;

involucres bowl-shaped, 6–15 mm, lobes 6–8, broadly lanceolate, margins entire, acuminate, apex 3–5-fid.

Peduncles

2–10 cm.

5–15 cm.

Pedicels

strongly reflexed, 2–3.5 mm;

bracteoles lanceolate, 1 mm.

straight, 0.5–1 mm;

bracteoles absent.

Flowers

8–12 mm;

calyx campanulate, 3.5–4 mm, glabrous or sparsely hairy, veins 10, tube 1.5–2 mm, lobes unequal, lanceolate-subulate, orifice open;

corolla pale to dark pink, 7–10 mm, banner ovate-oblong, 6.5–10.5 × 4–6 mm, apex rounded-denticulate.

12–14 mm;

calyx campanulate, 5–8 mm, glabrous, veins 10, tube 2.5–4 mm, lobes 11–15, unequal, abaxial 3–5 forked, adaxial unbranched, orifice open;

corolla creamy white to pinkish, 11–13 mm, banner ovate, inflated entire length in fruit, not distally twisted, 11–13 × 5–7 mm, apex rounded.

Legumes

stipitate, ellipsoid, 3–7 mm.

ellipsoid, 5–6 mm.

Seeds

2–4, tan, brown, or red-brown, mitten-shaped, 1–1.4 mm, smooth, dull.

1 or 2, gray-brown, black-mottled, subglobose, 2.5 mm, smooth.

2n

= 16.

Trifolium hybridum

Trifolium piorkowskii

Phenology Flowering May–Oct. Flowering Apr–May.
Habitat Roadsides, open woods, edges, fields, meadows, waste places. Shallow, vernally wet depres­sions on volcanic flats, banks of watercourses flowing through open rocky grassland, transitional habitats with scattered chaparral and conifers.
Elevation 0–1800 m. (0–5900 ft.) 300–800 m. (1000–2600 ft.)
Distribution
from FNA
AK; AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NL; NS; NT; ON; PE; QC; SK; YT; SPM; Greenland; Europe; w Asia [Introduced in North America; introduced also in South America, Europe, elsewhere in Asia, Africa, Pacific Islands, Australia]
[WildflowerSearch map]
[BONAP county map]
from FNA
CA
Discussion

Trifolium hybridum is widely cultivated as a forage crop. It may cause dermatitis in humans (J. W. Hardin and J. M. Arena 1974) and is implicated as a cause of dermatitis and biliary fibrosis in horses (C. Fisher 1995); the connection between the clover and the diseases is inconclusive (P. N. Nation 1989).

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

Trifolium piorkowskii is known only from Shasta County.

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

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. 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
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. 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
Synonyms Amoria hybrida, T. elegans
Name authority Linnaeus: Sp. Pl. 2: 766. (1753) Rand. Morgan & A. L. Barber: Novon, 23: 65, plate 1. (2014)
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