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Vascular Plants of California
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Melilotus officinalis

Higher Taxonomy
Family: Fabaceae (Leguminosae)View DescriptionDichotomous Key
Habit: Annual to tree. Leaf: generally alternate, generally compound, generally stipuled, generally entire, pinnately veined Inflorescence: generally raceme, spike, umbel or head; or flowers 1--few in axils. Flower: generally bisexual, generally bilateral; hypanthium 0 or flat to tubular; sepals generally 5, generally fused; petals generally 5, free, fused, or lower 2 +- united into keel (see 3, Key to Groups, for banner, wings); stamens 10 or many (or [1], 5, 6, 7, 9), free or fused or 10 with 9 filaments at least partly fused, 1 (uppermost) free; pistil 1, ovary superior, generally 1-chambered, ovules 1--many, style, stigma 1. Fruit: legume, including a stalk-like base (above receptacle) or not. Seed: 1--many, often +- reniform, generally hard, smooth.
Genera In Family: +- 730 genera, 19400 species: worldwide; with grasses, requisite in agriculture, most natural ecosystems. Many cultivated, most importantly Arachis, peanut; Glycine, soybean; Phaseolus, beans; Medicago, alfalfa; Trifolium, clovers; many orns. Note: Unless stated otherwise, fruit length including stalk-like base, number of 2° leaflets is per 1° leaflet. Upper suture of fruit adaxial, lower abaxial. Anthyllis vulneraria L. evidently a waif, a contaminant of legume seed from Europe. Laburnum anagyroides Medik., collected on Mount St. Helena in 1987, may be naturalized. Ceratonia siliqua L., carob tree (Group 2), differs from Gleditsia triacanthos L. in having evergreen (vs deciduous) leaves that are 1-pinnate (vs 1-pinnate on spurs on old stems, 2-pinnate on new stems) with 2--5(8) (vs 7--17) 1° leaflets, commonly cultivated, now naturalized in southern California. Aeschynomene rudis Benth. , Halimodendron halodendron (Pall.) Voss (possibly extirpated), Lens culinaris Medik. are agricultural weeds. Caragana arborescens Lam. only cult. Ononis alopecuroides L. , Sphaerophysa salsula (Pall.) DC. all evidently extirpated. Cercidium moved to Parkinsonia; Chamaecytisus to Cytisus; Psoralidium lanceolatum to Ladeania.
eFlora Treatment Author: Martin F. Wojciechowski, except as noted
Scientific Editor: Martin F. Wojciechowski, Thomas J. Rosatti.
Genus: MelilotusView DescriptionDichotomous Key

Habit: Annual, biennial, unarmed. Stem: generally erect. Leaf: odd-1-pinnate; stipules generally narrow or bristle-like, bases fused to petiole; leaflets 3, margin toothed or wavy. Inflorescence: raceme, axillary or terminal, slender or short-cylindric, many-flowered. Flower: calyx lobes +- equal; corolla yellow or white; 9 filaments fused, 1 free. Fruit: indehiscent, 2--4 mm, ovate, compressed but thick, leathery, bumpy or not, ridges transverse to finely net-like. Seed: 1--2.
Species In Genus: 20 species: temperate Europe, especially Mediterranean, subtropical Asia, northern Africa, widely introduced, naturalized; several species widely cultivated for forage, green manure, soil improvement. Etymology: (Greek: honey-lotus) Toxicity: TOXIC: inclusion in hay enhances production of mold toxins that may cause cattle death.
eFlora Treatment Author: Kelly Steele & Duane Isely
Unabridged Reference: Stevenson 1969 Can J Pl Sci 49:1--20
Melilotus officinalis Lam.
Habit: Biennial, +- glabrous to strigose. Stem: 0.5--2 m. Leaf: leaflets 1--2.5 cm, elliptic-oblong to obovate, +- toothed. Inflorescence: slender; axis generally 3--8 cm when flowers open, longer in fruit. Flower: calyx 2--2.5 mm; corolla 4.5--7 mm, yellow. Fruit: 3--5 mm, plump, irregularly cross-ridged. Seed: 1. Chromosomes: 2n=16.
Ecology: Open fields, disturbed sites, cultivated; Elevation: < 2300 m. Bioregional Distribution: CA; Distribution Outside California: widely distributed in temperate areas, especially northern and central United States; native to Eurasia. Flowering Time: May--Aug
Jepson eFlora Author: Kelly Steele & Duane Isely
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)

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Botanical illustration including Melilotus officinalis

botanical illustration including Melilotus officinalis


Citation for this treatment: Kelly Steele & Duane Isely 2012, Melilotus officinalis, in Jepson Flora Project (eds.) Jepson eFlora, /eflora/eflora_display.php?tid=33152, accessed on August 01, 2021.

Citation for the whole project: Jepson Flora Project (eds.) 2021, Jepson eFlora,, accessed on August 01, 2021.

Melilotus officinalis
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© 2015 Neal Kramer
Melilotus officinalis
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© 2015 Neal Kramer
Melilotus officinalis
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© 2008 Thomas Stoughton
Melilotus officinalis
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© 2015 Neal Kramer
Melilotus officinalis
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© 2016 Keir Morse
Melilotus officinalis
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© 2020 Barry Breckling

More photos of Melilotus officinalis in CalPhotos

Geographic subdivisions for Melilotus officinalis:
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map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).


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Data provided by the participants of the  Consortium of California Herbaria.
View all CCH records
All markers link to CCH specimen records. The original determination is shown in the popup window.
Blue markers indicate specimens that map to one of the expected Jepson geographic subdivisions (see left map). Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.

CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa, if there are more than 1 infraspecific taxon in CA.
Blue line denotes eFlora flowering time (fruiting time in some monocot genera).