Jepson eFlora: Taxon page
Vascular Plants of California
Key to families | Table of families and genera
Previous taxon Index to accepted names and synonyms:
| A | B | C | D | E | F | G | H | I | J | K | L | M |
| N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
Next taxon

Lemna minuta

Higher Taxonomy
Family: AraceaeView DescriptionDichotomous Key
Common Name: ARUM FAMILY
Habit: Perennial herb, [shrub, vine], terrestrial [growing on other plants or not], or aquatic, sometimes free-floating, then sometimes much reduced, in dense, clonal populations, 0.4--10 mm, flat and tongue-shaped to spheric, not differentiated into stems and leaves, new plants produced in budding pouch at base or along margins, sometimes overwintering on bottom as dense, rootless, starch-filled daughter plant (winter bud); often from short, generally erect caudex; roots 0--many; often monoecious. Stem: sometimes above ground in addition to caudex, or not differentiated from plant body. Leaf: simple or compound, basal (or cauline, 2-ranked), or not differentiated from plant body. Inflorescence: generally spike, fleshy, generally ill-smelling, or flower 1, rarely seen, minute, appearing like 2--3 unisexual flowers, often sheathed by minute membrane; flowers bisexual or pistillate below, staminate above; bract subtending spike 1, generally showy (petal-like), generally > spike, sheathing or not. Flower: perianth parts 0, 4, 6, free or fused; stamens 0--4, 6, free or fused; ovary superior to 1/2-inferior and sunken in inflorescence axis, chambers 1--3, stigma +- sessile. Fruit: berry or achene-like, winged or not. Seed: 1--many, often ribbed.
Genera In Family: +- 114 genera, 1850 species: generally tropics, subtropics some cultivated for food, ornamental in ponds, aquaria (Colocasia, taro) or ornamental (Philodendron, Anthurium). Note: Since TJM (1993), including Lemnaceae, and except Acorus, now in Acoraceae (the sole member in California, Acorus calamus L., is an historical waif). Pistia stratiotes L. is a waif. Pinellia ternata (Thunb.) Breitenbach possibly naturalized in California. In taxa once included in Lemnaceae, vein number per plant body best determined using backlight.
Unabridged Note: Since TJM (1993), including Lemnaceae, except Acorus, now in Acoraceae (the sole representative of the family in California, Acorus calamus, judged to be an historical waif in California and therefore here except). Incl smallest of all known angiosperms (Wolffia globosa) as well as world's most massive inflorescence (spike of Amorphophallus titanum, Titan Arum, to 4 m in circumference). Needle-like crystals in most tissues cause intense irritation when chewed; those of Dieffenbachia, dumb-cane, may induce temporary speechlessness. Incl of fossil evidence in cladistic analyses indicate Lemnaceae and Pistia form a monophyletic group within Araceae (Stockey et al.), a position now generally accepted (see Les et al.). Pinellia ternata (Thunb.) Makino ex Breitenbach introduced, possibly naturalized in California. Taxa formerly included in Lemnaceae may be very invasive. In taxa formerly included in Lemnaceae, vein number per plant body best determined using backlight. Peltandra virginica (L.) Schott & Endl., included in TJM (1993), reportedly spread from ornamental pool introduction in 1970 to nearby reserviors, but degree of reproduction or even persistence there unknown.
eFlora Treatment Author: Thomas J. Rosatti, except as noted
Scientific Editor: Bruce G. Baldwin, Thomas J. Rosatti.
Genus: LemnaView DescriptionDichotomous Key

Common Name: DUCKWEED
Habit: Plants much reduced, not differentiated into stems, leaves; floating aquatic; root generally 1, generally 2--6 mm, sheath near base generally not winged. Plant Body: generally in 2s to 8s; generally 2--5 mm, flat, generally widely elliptic to oblong, pale to dark green, often +- red; veins 1--5; winter buds generally 0. Inflorescence: flowers in 2 lateral pouches, sheathed by minute membrane. Fruit: generally unwinged. Seed: ribbed, generally smooth between ribs.
Etymology: (Greek: lake or swamp) Note: Lemna obscura (Austin) Daubs. [Lemna minor L. var. obscura Austin] excluded.
eFlora Treatment Author: Wayne P. Armstrong
Lemna minuta Kunth
Plant Body: generally in 2s (especially when crowded, in full sun); 1--2.5 mm, widely elliptic to oblong, pale green, generally thinner at margin, base, tip generally symmetric; vein 1, obscure, < 2/3 distance from root attachment to tip of plant body, generally not exceeding region of visible air spaces between cells. Seed: cross-lined between ribs.
Ecology: Common. Freshwater; Elevation: < 2200 m. Bioregional Distribution: NCo, NCoR, SN, SnJV, CW (exc SCoRO), SCo, SnGb, PR, D; Distribution Outside California: western United States, South America, Europe, northern Asia. Flowering Time: Aug Note: Transparent green pls, 2--4 mm, in 4s, much like Lemna valdiviana, possibly in response to growth conditions, need study.
Synonyms: Lemna minima Hegelm., illeg.; Lemna minuscula Herter
Jepson eFlora Author: Wayne P. Armstrong
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)

Previous taxon: Lemna minor
Next taxon: Lemna trisulca

Name Search

Please use this Google Form for Contact/Feedback

Citation for this treatment: Wayne P. Armstrong 2012, Lemna minuta, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on February 24, 2024.

Citation for the whole project: Jepson Flora Project (eds.) 2024, Jepson eFlora,, accessed on February 24, 2024.

Lemna minuta
click for enlargement
©2014 Neal Kramer
Lemna minuta
click for enlargement
©2020 Neal Kramer
Lemna minuta
click for enlargement
©2012 Barry Rice
Lemna minuta
click for enlargement
©2014 Neal Kramer
Lemna minuta
click for enlargement
©2014 Neal Kramer

More photos of Lemna minuta
in CalPhotos

Geographic subdivisions for Lemna minuta:
NCo, NCoR, SN, SnJV, CW (exc SCoRO), SCo, SnGb, PR, D
1. You can change the display of the base map layer control box in the upper right-hand corner.
2. County and Jepson Region polygons can be turned off and on using the check boxes.
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).


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).