Melilotus albus |
Melilotus officinalis |
|
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honey-clover, white melilot, white sweet-clover |
common melilot, field or rib or yellow melilot, rib melilot, sweetclover, yellow melilot, yellow sweet-clover |
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Habit | Herbs usually biennial, rarely annual, 30–150(–260) cm. | Herbs usually biennial, sometimes annual, (15–)30–280 cm. |
Stems | erect or ascending. |
decumbent to erect. |
Leaves | stipules lanceolate-subulate to setaceous, 4–6(–10) mm, margins usually entire, sometimes toothed at base; leaflet blades narrowly oblong-obovate to suborbiculate-oblong, 10–24(–50) × 5–12(–15) mm, margins dentate. |
stipules lanceolate or subulate, 3–6(–12) mm, margins entire; leaflet blades obovate, obovate-oblong, ovate, or ovate-lanceolate, 8–25 × 4–15 mm, margins dentate. |
Racemes | 40–80(–120)-flowered. |
30–70(–80)–flowered. |
Pedicels | 1–1.5(–2) mm. |
(1.5–)2–2.5 mm. |
Flowers | 3.5–5(–6) mm; corolla white; ovary glabrous. |
4–7 mm; corolla yellow; ovary glabrous. |
Legumes | obovoid, subglobose, or globose-ovoid, 3–5 mm, reticulate-veined, glabrous. |
ovoid, 2.5–5 mm, transversely rugose, areoles notably elongated, glabrous. |
Seeds | 1 or 2(or 3), ovoid, (1.7–)2–2.5(–3.5) mm. |
1 (or 2), ovoid, obovoid, or ellipsoid, (1.5–)1.8–2(–2.5) mm. |
2n | = 16. |
= 16. |
Melilotus albus |
Melilotus officinalis |
|
Phenology | Flowering spring–fall. | Flowering spring–fall. |
Habitat | Grasslands, mixed forests, canyons, streamsides, riverbeds, lakeshores, waste places, roadsides. | Grasslands, slopes, plains, hillsides, waste places, roadsides, cultivated fields. |
Elevation | 0–2700 m. (0–8900 ft.) | 0–3100 m. (0–10200 ft.) |
Distribution |
AK; AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NL; NS; NT; NU; ON; PE; QC; SK; YT; SPM; Greenland; Eurasia [Introduced in North America; introduced also in Mexico, West Indies, South America, Australia]
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AK; AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NL; NS; NT; ON; PE; QC; SK; YT; Eurasia [Introduced in North America; introduced also in Mexico, South America, Africa, Australia]
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Discussion | Melilotus albus is extremely variable in Eurasia, and has been divided into many infraspecific taxa. It is the most important economic species in Melilotus, often grown as a crop, green manure, and honey plant, and posing a widespread weed problem. Essentially all white-petaled Melilotus plants growing outside of cultivation in North America are M. albus; herbarium specimens often do not show the color well, sometimes resulting in misidentification, particularly between M. albus and M. officinalis. Aside from petal color, the species are quite similar. The venation areolae on the mature pods tend to differ: the raised venation ridges tend to form an irregular reticulation on the mature fruits of M. albus; they tend to form transverse areolae on the fruits of M. officinalis (S. J. Darbyshire and E. Small 2018). Although M. albus and M. officinalis are sometimes merged, there are very strong barriers to interbreeding between the two (G. T. Webster 1955; M. Maekawa et al. 1991), in addition to geographical and ecological differences, which justify their continued recognition as separate species. P. Coulot and P. Rabaute (2013) included Melilotus albus in Trigonella sulcata (Desfontaines) Coulot & Rabaute (treated here as M. sulcatus). Most botanical literature incorrectly lists the authority for Melilotus albus as Desrousseaux in Lamarck instead of Medikus. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Melilotus officinalis is occasionally grown as a forage crop, but it is generally considered to be an undesirable weed. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 11. | FNA vol. 11. |
Parent taxa | Fabaceae > subfam. Faboideae > Melilotus | Fabaceae > subfam. Faboideae > Melilotus |
Sibling taxa | ||
Synonyms | Trifolium officinale, Trigonella officinalis | |
Name authority | Medikus: Vorles. Churpfälz. Phys.-Ökon. Ges. 2: 382. (1787) — (as alba) | (Linnaeus) Lamarck: Fl. Franç. 2: 594. (1779) |
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