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elongated clover, productive clover, Shasta clover

canyon clover, Howell's clover

Habit Herbs perennial, 15–45 cm, glabrous. Herbs perennial, 30–100 cm, glabrous.
Stems

± erect, loosely cespitose, branched.

erect, fistulose, unbranched or branched distally.

Leaves

basal and cauline, palmate;

stipules ovate-lanceolate, 0.5–2 cm, margins usually entire, sometimes lobed, apex acute to acuminate;

petiole 0.5–12 cm;

petiolules 1 mm;

leaflets 3, blades lanceolate or elliptic, 0.5–2 × 0.3–1.3 cm, base cuneate, veins prominent, margins serrate, apex acute, apiculate, surfaces glabrous.

palmate;

stipules ovate, 1.5–4.5 cm, margins usually entire, sometimes lobed, apex acuminate;

petiole 0.5–20 cm;

petiolules 1–1.5 mm;

leaflets 3, blades ovate, elliptic, or rhombic, 3.5–9.5 × 2.3–5 cm, base cuneate, veins obscure, margins ± serrate, apex acute, rounded, or obtuse, surfaces glabrous.

Inflorescences

terminal or axillary, 15–30-flowered, ellipsoid or conic, 1.5–2 × 1–3 cm, rachis prolonged beyond flowers, undivided or forked, often bearing sterile flower buds distally;

involucres absent.

terminal or axillary, 20–70-flowered, globose or ellipsoid, 2.5–4 × 2–2.5 cm, rachis prolonged beyond flowers, undivided or forked, often bearing sterile flower buds distally;

involucres absent.

Peduncles

2–13 cm, slightly twisted apically.

3–11 cm.

Pedicels

strongly reflexed in fruit, 0.5 mm;

bracteoles minute, lanceolate.

strongly reflexed in fruit, 1 mm;

bracteoles minute, blunt or acute, membranous.

Flowers

12–14 mm;

calyx pink to purple, campanulate, 3–3.5 mm, glabrous, veins 10 (5 sometimes faint), tube 1.5–1.7 mm, lobes subequal, triangular-subulate, orifice open;

corolla pink to deep purple, 12–14 mm, banner oblong, 12–14 × 4–5 mm, apex rounded or retuse.

10–14 mm;

calyx campanulate, gibbous, 4–5.5 mm, glabrous, veins 10, tube 2–2.5 mm, lobes subequal, linear-lanceolate, orifice open;

corolla white, lemon yellow, or greenish yellow, 11–12 mm, banner elliptic-oblong, 11–12 × 4–5 mm, apex obtuse.

Legumes

obliquely ellipsoid, 5 mm.

oblong or clavate, 4–5 mm.

Seeds

1 or 2, brown, often purple-mottled, flattened ovoid, 2–3 mm, smooth.

1–3, reddish black or brown, angular, mitten-shaped, 2.5 mm, smooth or slightly roughened, dull.

2n

= 16.

Trifolium productum

Trifolium howellii

Phenology Flowering May–Sep. Flowering Jun–Jul.
Habitat Open coniferous woods, rocky places, stream banks, grassy meadows, near springs. Wet stream banks, wet meadows, flood plains, shady woodlands, springs, thickets.
Elevation 1100–2800 m. (3600–9200 ft.) 800–2000 m. (2600–6600 ft.)
Distribution
from FNA
CA; NV; OR
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; OR
[WildflowerSearch map]
[BONAP county map]
Discussion

Trifolium productum is morphologically most similar to T. kingii, from which it differs by its glabrous calyces and inflorescence rachises surpassing the flowers to 1.5 cm and apically forked (M. Zohary and D. Heller 1984). Trifolium productum is geographically isolated from T. kingii; the former is restricted to northern California, western Oregon, and western Nevada, while the latter is restricted to Utah and easternmost Nevada (J. M. Gillett 1972).

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

Trifolium howellii is known from Del Norte, Humboldt, Siskiyou, and Trinity counties in California, and Clackamas, Douglas, Jackson, Josephine, Klamath, Lane, and Linn counties in Oregon (J. M. Gillett 1972). It has some of the largest leaves of any species of Trifolium in North America.

(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. 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. 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. 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
Synonyms T. kingii subsp. productum, T. kingii var. productum
Name authority Greene: Erythea 2: 181. (1894) S. Watson: Proc. Amer. Acad. Arts 23: 262. (1888)
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