The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

showy Indian clover, two-fork clover

long-stalk clover

Habit Herbs annual, 45–65 cm, canescent. Herbs perennial, 5–46 cm, slightly pilose.
Stems

erect, branched from base and distally, or unbranched.

erect or ascending, cespitose, unbranched to sparsely branched distally.

Leaves

palmate;

stipules ovate-oblong, 0.5–1.8 cm, margins entire, toothed, or irregularly lobed, apex acuminate;

petiole 0.5–10 cm;

petiolules to 1 mm;

leaflets 3, blades broadly obovate or elliptic, 1.7–3.3 × 1.1–2 cm, base cuneate, veins fine, margins entire or denticulate, apex rounded, obtuse, or retuse, surfaces pilose, abaxial less so.

palmate;

stipules ovate to lanceolate, 1–5 cm, margins usually entire, sometimes slightly serrate proximally, apex acute or acuminate;

petiole 1–13 cm;

petiolules to 1 mm;

leaflets 3, blades linear, lanceolate to elliptic, or oblong, cauline sometimes ovate, 0.8–6 × 0.2–1.6 cm, base cuneate, veins slightly to very thickened, arching, margins entire or serrate, apex acute, surfaces glabrous abaxially, usually appressed-pubescent adaxially.

Inflorescences

terminal or axillary, 30–50-flowered, bluntly conic, ellipsoid, globose, or subglobose, 1.5–3 × 1.5–2.5 cm;

involucres absent.

terminal, 10–40-flowered, globose, ellipsoid, obconic, or subglobose, 1–3.5 × 1–3.2 cm;

involucres absent.

Peduncles

5–15 cm.

1–30 cm.

Pedicels

absent;

bracteoles cuplike, to 0.5 mm.

erect or reflexed in fruit, 0.5–2 mm;

bracteoles scalelike, 0.5 mm.

Flowers

13–16 mm;

calyx tubular, 9–12 mm, pubescent, veins 20–30, tube 3 mm, lobes nearly equal, appearing rigidly erect, linear-setaceous, plumose, sinuses acute, orifice open;

corolla white to pink with purple tips, 12–16 mm, banner ovate-oblong, 12–15 × 4 mm, apex broadly rounded, emarginate.

10–19 mm;

calyx tubular, 4–10 mm, hairy or glabrous, veins 5–10, tube 2.5–3 mm, lobes unequal, linear, shorter than or to 6 times tube, orifice open;

corolla white, cream, pink, lavender, or purple, sometimes pale with purple tips, 10–18 mm, petals not beaked except subsp. multipedunculatum, banner ovate to oblanceolate, 10–18 × 3–4 mm, apex usually not beaked, usually obtuse, acute, or acuminate, rarely emarginate;

ovaries pubescent distally.

Legumes

obovoid, 4 mm.

oblong to ellipsoid, 4–5 mm.

Seeds

1, dark brown, ellipsoid, 2–3 mm, smooth.

1–4, dark brown, flattened globose, 2–3 mm, smooth.

Trifolium amoenum

Trifolium longipes

Phenology Flowering Apr–May.
Habitat Grassy slopes, swales, clay soils.
Elevation 0–100 m. (0–300 ft.)
Distribution
from FNA
CA
[WildflowerSearch map]
[BONAP county map]
from USDA
w United States
[WildflowerSearch map]
[BONAP county map]
Discussion

Trifolium amoenum was considered extinct (J. P. Smith Jr. 1984) but was rediscovered in 1993 (P. G. Connors 1994). Specimens of T. amoenum are known from Marin, Napa, San Mateo, Solano, and Sonoma counties; it appears to be extant in only single populations in each of Marin and Solano counties. Allozyme studies of the two known populations revealed fixed genetic differences between them (E. E. Knapp and Connors 1999).

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

Subspecies 12 (12 in the flora).

Trifolium longipes encompasses a morphologically diverse and taxonomically difficult suite of populations. J. M. Gillett (1969) united T. longipes with T. rusbyi and differentiated ten subspecies, with T. neurophyllum recognized as distinct. M. Zohary and D. Heller (1984) maintained T. rusbyi (with seven subspecies, including subsp. neurophyllum) as distinct from T. longipes (with five subspecies). Analyses of molecular data support the union of T. longipes and T. rusbyi (N. W. Ellison et al. 2006).

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

Key
1. Banner, wing, and, often, keel petals beaked.
subsp. multipedunculatum
1. Banner, wing, and keel petals without beaks, banner apex acute to attenuate.
→ 2
2. Pedicels erect or proximalmost horizontal or slightly reflexed in fruit.
→ 3
3. Herbs rhizomatous; roots not fusiform, sometimes thickened.
→ 4
4. Calyx lobes lax, usually slightly longer than tube length, tube veins not promi­nent; leaflet blades lanceolate, elliptic to oblong, or ovate.
subsp. hansenii
4. Calyx lobes often ± rigid, 6 times tube length, tube veins usually prominent; leaflet blades linear to elliptic-linear or broadly elliptic.
subsp. elmeri
3. Herbs not rhizomatous (stems ascending from crowns); roots thickened, often fusiform.
→ 5
5. Banner and wing apices slender-acuminate.
subsp. longipes
5. Banner and wing apices usually acute or obtuse, rarely emarginate.
→ 6
6. Calyces and distal ends of peduncles densely pilose; banner apex acute.
subsp. atrorubens
6. Calyces and distal ends of peduncles sparsely pilose or glabrous; banner apex usually broad, acute or obtuse, rarely emarginate.
subsp. pedunculatum
2. Pedicels (at least proximal ones, usually all), strongly reflexed in fruit.
→ 7
7. Herbs with thickened roots, often fusiform, with crown of buried stems.
subsp. pygmaeum
7. Herbs usually rhizomatous, if rarely with roots ± thickened, then with crown of rhizomes above thickened portion, or with slender taproots bearing a crown of wiry, pilose stems.
→ 8
8. Pedicels slender, 1.5–2 mm; herbs with slender taproots, bearing crown of wiry, pilose stems.
subsp. oreganum
8. Pedicels stout, to 1 mm; herbs rhizomatous.
→ 9
9. Inflorescences globose or ellipsoid; proximal pedicels more strongly reflexed than distal ones.
→ 10
10. Inflorescences 18–22-flowered, globose, 2.2–2.5 cm diam.; flow­ers 10–13 mm, corollas purple, sometimes tips white.
subsp. shastense
10. Inflorescences 28–32-flowered, ellipsoid, 3–3.2 cm diam.; flow­ers 14–16 mm, corollas lavender.
subsp. caurinum
9. Inflorescences hemispheric, obconic, or sub­glo­bose; all pedicels strongly reflexed.
→ 11
11. Calyces sparsely pilose or curly-pilose at sinuses, often glabrous proximally; corollas white, cream, or violet.
subsp. reflexum
11. Calyces white-villous, veins and lobes green; corollas purple-violet or lavender.
subsp. neurophyllum
Source FNA vol. 11. FNA vol. 11.
Parent taxa Fabaceae > subfam. Faboideae > Trifolium Fabaceae > subfam. Faboideae > Trifolium
Sibling taxa
T. albopurpureum, T. alexandrinum, 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. 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. 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
Subordinate taxa
T. longipes subsp. atrorubens, T. longipes subsp. caurinum, T. longipes subsp. elmeri, T. longipes subsp. hansenii, T. longipes subsp. longipes, T. longipes subsp. multipedunculatum, T. longipes subsp. neurophyllum, T. longipes subsp. oreganum, T. longipes subsp. pedunculatum, T. longipes subsp. pygmaeum, T. longipes subsp. reflexum, T. longipes subsp. shastense
Name authority Greene: Fl. Francisc., 27. (1891) Nuttall in J. Torrey and A. Gray: Fl. N. Amer. 1: 314. (1838)
Web links