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foothill clover, tree clover

marshmallow clover, Piorkowski's clover

Habit Herbs annual, 5–50 cm, glabrous or sparsely hairy. Herbs annual, 7–30 cm, glabrous.
Stems

erect, branched.

erect or ascending, sparsely to much branched.

Leaves

palmate;

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

petiole 1–13 cm;

petiolules 0.5 mm;

leaflets 3, blades elliptic to oblong or obovate, 0.8–3.5 × 0.5–1.5 cm, base cuneate, veins thickened, margins serrate proximally, obscurely denticulate distally, apex usually rounded or retuse, rarely acute, 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

axillary or terminal, 10–30-flowered, ovoid to subglobose, 0.7–2.2 × 0.5–2 cm;

involucres a narrow rim, 0.5 mm, membranous, dentate.

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

2.5–12 cm.

5–15 cm.

Pedicels

erect becoming reflexed, 0.5–6 mm;

bracteoles linear or cup-shaped, to 1 mm.

straight, 0.5–1 mm;

bracteoles absent.

Flowers

6–13 mm;

calyx broadly campanulate, 5–11 mm, glabrous, veins 10, tube 1–5 mm, lobes unequal, elliptic to linear, margins hyaline, dentate or pectinate, ciliate, sinuses narrow, orifice open;

corolla white, pink, or purple, 5–13 mm, banner broadly ovate, 6–13 × 4–7 mm, apex rounded, apiculate.

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

short-stipitate, ovoid, 5–10 mm.

ellipsoid, 5–6 mm.

Seeds

1 or 2, brown, mottled, ovoid, 2.5–3 mm, smooth.

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

2n

= 16.

Trifolium ciliolatum

Trifolium piorkowskii

Phenology Flowering Apr–Jun. Flowering Apr–May.
Habitat Oak-pine chaparral, meadows, roadsides. Shallow, vernally wet depres­sions on volcanic flats, banks of watercourses flowing through open rocky grassland, transitional habitats with scattered chaparral and conifers.
Elevation 0–1500 m. (0–4900 ft.) 300–800 m. (1000–2600 ft.)
Distribution
from FNA
CA; OR; WA; Mexico (Baja California)
[WildflowerSearch map]
[BONAP county map]
from FNA
CA
Discussion

Trifolium ciliolatum is relatively widespread in California and is found in scattered sites in Baja California, Oregon, and Washington.

Trifolium ciliatum Nuttall (1848), which pertains here, is a later homonym of T. ciliatum E. D. Clarke (1813).

(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. 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. 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 T. ciliatum var. discolor
Name authority Bentham: Pl. Hartw., 304. (1849) Rand. Morgan & A. L. Barber: Novon, 23: 65, plate 1. (2014)
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