Contains 20 accepted taxa overall.
Characteristics
Classification
Citation
TRIFOLIUM Linnaeus, Sp. Pl. 764. 1753.
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TYPE: Trifolium pratense Linnaeus Lectotypified by Britton & A. Brown, Ill. Fl. N. U.S., ed. 2. 2: 353. 1913.
Species
| Scientific Name | Common Name | Herbarium Specimens | Status | Photos |
|---|---|---|---|---|
| Trifolium angustifolium | Narrowleaf Clover | |||
| Trifolium arvense | Rabbitfoot Clover | |||
| Trifolium aureum | Large Hop Clover, Yellow Clover | |||
| Trifolium campestre | Hop Clover | |||
| Trifolium carolinianum | Wild White Clover, Carolina Clover | |||
| Trifolium cernuum | Nodding-head Clover | |||
| Trifolium depauperatum var. depauperatum | Cowbag Clover, Balloon-sack Clover, Poverty Clover | |||
| Trifolium dubium | Low Hop Clover, Little Hop Clover | |||
| Trifolium glomeratum | ||||
| Trifolium gracilentum | Pinpoint Clover | |||
| Trifolium hybridum | Alsike Clover | |||
| Trifolium incarnatum | Crimson Clover | |||
| Trifolium pratense | Red Clover | |||
| Trifolium reflexum | Buffalo Clover | |||
| Trifolium repens | White Clover, Dutch Clover, Ladino Clover | |||
| Trifolium resupinatum | Persian Clover, Reversed Clover | |||
| Trifolium striatum | Knotted Clover | |||
| Trifolium subterraneum | Subterranean Clover | |||
| Trifolium tomentosum | Wooly Clover | |||
| Trifolium vesiculosum | Arrowleaf Clover |
Identification Key
1. Corolla bright yellow
2
1. Corolla white, pink, to red
3
2. Stipules 5-8 mm long; leaflets rhombic to obovate; corolla 4-6 mm long, the upper petal striate or ribbed, plane or nearly so; inflorescence 8-13 mm wide, mostly with 20-60 flowers
2. Stipules 3-5 mm long; leaflets obovate to elliptic-lanceolate; corolla 2.5-4 mm long, the upper petal scarcely striate or ribbed or not at all, longitudinally folded; inflorescence 5-8 mm wide, mostly with 3-20 flowers
3. Pedicels 1-10 mm long
4
3. Pedicels 0-1 mm long
8
4. Plant stoloniferous; peduncles arising from the stolon
4. Plant not stoloniferous; peduncles arising from aboveground nodes of the stem
5
5. Stipules lanceolate, subequal to the stem width, scarious, sometimes green only in the upper half; calyx glabrate (except for tufts at the base)
6
5. Stipules ovate, often wider than the stem, most of the blade green when young, sometimes scarious at the base; calyx pilose (sometimes sparsely so)
7
6. Leaflets 1-4 cm long; calyx lobes not scarious-margined
6. Leaflets 0.6-2.5 cm long; calyx lobes scarious-margined
7. Calyx lobes lanceolate, foliaceous, 3-veined; inflorescence 1-1.5 cm wide; corolla 4-7 mm long
7. Calyx lobes subulate, setaceous, 1-veined; inflorescence 2-4 cm wide; corolla 8-12 mm long
8. Inflorescence subsessile and involucrate, subtended by 2 broad stipules and 1-2 leaves
9
8. Inflorescence pedunculate (occasionally subsessile, the peduncle mostly >2 mm long), without stipules and leaves directly under the head
10
9. Stipules with an acuminate tip; calyx subappressed pubescent, the tube 20-nerved
9. Stipules with a filamentous, awned tip; calyx sparsely pilose, the tube 10-nerved
10. Calyx bladder-like, becoming inflated in fruit
11
10. Calyx not bladder-like, becoming inflated in fruit
13
11. Calyx tube 4-6 mm long; corolla not resupinate; fruit with 4-6 mm long, (1-)3-4 seeds
11. Calyx tube 1-2 mm long; corolla resupinate; fruit 1.5-2 mm long, with 1 seed
12
12. Peduncle 6-60 mm long; calyx short-hairy to glabrate, the apical teeth prolonged and conspicuous, especially in fruit, the calyx tube 7-9 mm long in fruit
12. Peduncle to 15 mm long, often much shorter; calyx woolly, the apical teeth short and usually concealed, the calyx tube 4-5 mm long in fruit
13. Corolla 3-8 mm long, subequal to shorter than the calyx
14
13. Corolla 9-18 mm long, subequal to longer than the calyx
15
14. Leaflets mostly oblong to narrowly obovate, <3 mm wide; inflorescence head elongate, cylindric; calyx tube pubescent, 10-nerved, the lobes 1-nerved
14. Leaflets mostly obovate, >3 mm wide; inflorescence head globose; calyx tube glabrous, 20-nerved, the lobes with 2 or more nerves
15. Inflorescence 1-2 cm wide, without floral bracts; calyx pilose, 10-nerved, not cross-reticulate; corolla red (rarely white); calyx not inflated in fruit
15. Inflorescence 2.5-3 cm wide, with floral bracts; calyx glabrate to sparsely pilose at the tip, 20-nerved, cross-reticulate; corolla white; calyx inflated in fruit
Genus Synonyms
| Synonym | Full Citation | Basionym | Type |
|---|---|---|---|
| No synonyms found. | |||