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field clover, hop clover, hop trefoil, low hop-clover, pinnate hop clover

plumed clover

Habit Herbs annual, 5–40 cm, slightly villous or glabrous. Herbs perennial, 10–60 cm, villous.
Stems

erect to ascending, branched.

erect, branched or unbranched.

Leaves

pinnate;

stipules ovate-lanceolate, 0.5–0.8 cm, margins entire, glandular, apex acuminate;

petiole 0.3–2 cm;

lateral leaflet petiolules 0.5–0.6 mm, terminal leaflet stalk 3–5 mm;

leaflets 3, blades rhombic to obovate, 0.4–1.5 × 0.4–0.8 cm, base cuneate, lateral veins prominent, ± parallel, ascending, margins denticulate distally, apex truncate or retuse, surfaces strigose adaxially.

palmate;

stipules linear, oblong, or ovate, 1.5–2.5 cm, margins entire or slightly serrulate, apex acute to acuminate;

petiole 1–20 cm;

petiolules to 0.5 mm;

leaflets 3, blades linear, elliptic, oblong, or lanceolate-elliptic, often folded, falcate, 4–11 × 0.1–1.6 cm, base cuneate, veins thickened, margins denticulate, apex acute or acuminate, surfaces villous.

Inflorescences

axillary, 30–60-flowered, globose or broadly ovoid, 0.8–1.5 × 0.7–1 cm;

involucres absent.

terminal, 70–80-flowered, spicate, ovoid to cylindric, 3–6 × 2.5–3 cm;

involucres absent.

Peduncles

1.5–3.5 cm.

2–6 cm.

Pedicels

reflexed, 0.7–1.2 mm;

bracteoles a fringe of red setae.

erect or absent, 0–0.5 mm;

bracteoles absent.

Flowers

4.3–5 mm;

calyx campanulate, strongly bilabiate, 1.3–1.5 mm, glabrous, veins 5, tube 0.3–0.6 mm, lobes unequal, adaxial deltate, very short, lateral and abaxial linear-subulate, each tipped with 1 or 2 stiff hairs, orifice open;

corolla yellow becoming brown, 3.5–6 mm, ribbed, banner persistent, obovate, enveloping other petals, boat-shaped, 4.3–5 × 2.8–3.2 mm, apex broad, acute.

17–18 mm;

calyx campanulate, 5 mm, villous, veins 20, tube 2.5 mm, lobes subequal, subulate, straight, orifice open;

corolla creamy white, keel petals crimson, 12–22 mm, banner oblong, 12–22 × 3–5 mm, apex acute;

ovaries glabrous or pubescent distally.

Legumes

stipitate, oblong, 2–2.5 mm.

obovoid, 4–5 mm.

Seeds

1 or 2, yellow, ellipsoid, 1–1.5 mm, smooth, lustrous.

1–3, reddish brown or tan, ellipsoid, 1.8–2 mm, smooth, glossy.

2n

= 14.

= 32.

Trifolium campestre

Trifolium plumosum

Phenology Flowering Jun–Aug.
Habitat Roadsides, fields.
Elevation 0–1700 m. (0–5600 ft.)
Distribution
from FNA
AK; AL; AR; AZ; CA; 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; NY; OH; OK; OR; PA; RI; SC; TN; TX; VA; VT; WA; WI; WV; WY; BC; NB; NF; NS; ON; PE; QC; SPM; Europe; w Asia; n Africa [Introduced in North America; introduced also in South America, e Asia (China), s Africa, Pacific Islands (Hawaii, New Zealand), Australia]
[WildflowerSearch map]
[BONAP county map]
from USDA
nw United States
[WildflowerSearch map]
[BONAP county map]
Discussion

Trifolium filiforme Linnaeus and T. procumbens Linnaeus are rejected names that were used historically for T. campestre (J. E. Dandy 1958; N. J. Turland et al. 1996).

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

Subspecies 2 (2 in the flora).

J. M. Gillett (1972) stated that the leaflet width in the basal leaves is the best distinction between the two subspecies, which are geographically isolated.

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

Key
1. Leaflet blades of basal leaves 0.2–0.5(–0.7) cm wide, apex acuminate; herbs 20–35 cm.
subsp. plumosum
1. Leaflet blades of basal leaves (0.8–)0.9–1.6 cm wide, apex acute; herbs 10–60 cm.
subsp. amplifolium
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. 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. 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. piorkowskii, 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. plumosum subsp. amplifolium, T. plumosum subsp. plumosum
Synonyms Chrysaspis campestris
Name authority Schreber in G. F. Hoffmann: Deutschl. Fl. 4: 16, plate 253. (1804) Douglas in W. J. Hooker: Fl. Bor.-Amer. 1: 130, plate 49. (1831)
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