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canyon clover, Howell's clover

elongated clover, productive clover, Shasta clover

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

erect, fistulose, unbranched or branched distally.

± erect, loosely cespitose, branched.

Leaves

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.

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.

Inflorescences

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.

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.

Peduncles

3–11 cm.

2–13 cm, slightly twisted apically.

Pedicels

strongly reflexed in fruit, 1 mm;

bracteoles minute, blunt or acute, membranous.

strongly reflexed in fruit, 0.5 mm;

bracteoles minute, lanceolate.

Flowers

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.

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.

Legumes

oblong or clavate, 4–5 mm.

obliquely ellipsoid, 5 mm.

Seeds

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

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

2n

= 16.

Trifolium howellii

Trifolium productum

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

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.)

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.)

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