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

carpet clover, mountain carpet clover

Habit Herbs annual, 45–65 cm, canescent. Herbs perennial, 3–22 cm, glabrous or hairy, often mat-forming.
Stems

erect, branched from base and distally, or unbranched.

decumbent to ascending, much-branched.

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, 0.3–1.2 cm, margins entire, serrate, or slightly lacerate, apex acute to acuminate;

petiole 1–4.5 cm;

petiolules 0.1–0.5 mm;

leaflets 3, blades obovate, oblanceolate, or elliptic, 0.3–2 × 0.2–0.5 cm, base cuneate, veins prominent, margins ± dentate, serrate, or setose, apex acute, rounded, or retuse, surfaces glabrous or slightly villous.

Inflorescences

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

involucres absent.

axillary or terminal, 1–9-flowered, solitary or subglobose, 1–1.6 × 0.3–1.2 cm;

involucres campanulate, 2–5 mm, incised nearly to base, lobes 2–8, lanceolate.

Peduncles

5–15 cm.

0.5–2 cm.

Pedicels

absent;

bracteoles cuplike, to 0.5 mm.

erect, 1 mm;

bracteoles absent.

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.

10–16 mm;

calyx tubular, 2–10 mm, glabrous or pubescent, veins 10, tube 4–7 mm, lobes equal, triangular-subulate, orifice open;

corolla white, pink, or lavender, keel petals usually purple-spotted, 8–16 mm, banner oblong, 8–13 × 2–5 mm, apex emarginate.

Legumes

obovoid, 4 mm.

oblong, 2–4 mm.

Seeds

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

1 or 2, brown, mottled, mitten-shaped, 1–2 mm, dull.

2n

= 16.

Trifolium amoenum

Trifolium monanthum

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; nw Mexico
[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 4 (4 in the flora).

Morphological intergradation among subspecies of Trifolium monanthum may be indicative of low genetic barriers to crossing. It might be just as plausible to divide T. mononathum into two species instead of four subspecies (J. M. Gillett 1980), with T. monanthum encompassing populations with white rhizomes, and T. multicaule encompassing populations with taproots.

Trifolium monanthum often forms dense mats.

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

Key
1. Herbs glabrous or sparsely hairy, mat-forming; stems from thin to thick woody roots, rhizomes slender, white; peduncles straight or bent upwards at steep angle distally; flowers 1–5.
→ 2
2. Inflorescences (1 or)2–4-flowered; peduncles straight; leaflet blades obovate to oblanceo­late, margins ± dentate, apex rounded or retuse.
subsp. monanthum
2. Inflorescences 1–5-flowered; peduncles bent upwards at steep angle distally; leaflet blades oblanceolate or elliptic, margins setose, apex acute.
subsp. grantianum
1. Herbs densely hairy, decumbent to ascending; stems from thickened woody taproots, rhizomes absent; peduncles bent upwards at steep angle distally; flowers 1–9.
→ 3
3. Leaflet blade apex rounded, margins dentate.
subsp. parvum
3. Leaflet blade apex acute, margins serrate or setose.
subsp. tenerum
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. longipes, T. lupinaster, T. macilentum, T. macraei, T. macrocephalum, T. medium, T. microcephalum, T. microdon, 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. monanthum subsp. grantianum, T. monanthum subsp. monanthum, T. monanthum subsp. parvum, T. monanthum subsp. tenerum
Name authority Greene: Fl. Francisc., 27. (1891) A. Gray: Proc. Amer. Acad. Arts 6: 523. (1865)
Web links