View source for Lemna ← Lemna You do not have permission to edit this page, for the following reason: The action you have requested is limited to users in the group: Users. You can view and copy the source of this page. {{Treatment/ID |accepted_name=Lemna |accepted_authority=Linnaeus |publications={{Treatment/Publication |title=Sp. Pl. |place=2: 970. 1753; Gen. Pl. ed. 5; 417, 1754 |year=1754 }} |common_names=Duckweed;lenticules |basionyms= |synonyms= |hierarchy=Lemnaceae;Lemna |hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Lemnaceae]]</div><div class="higher-taxon"><small>genus</small>[[Lemna]]</div></div> |etymology=Greek name of a water plant |volume=Volume 22 |mention_page= |treatment_page=page 146 }}<!-- --><span class="statement" id="st-undefined" data-properties=""><b>Roots </b>1 per frond. <b>Fronds</b> floating or submersed, 1 or 2–20 or more, coherent in groups or forming chains, lanceolate-ovate, flat or gibbous, 1–15 mm, margins entire or denticulate, upper surfaces sometimes with small conic papillae along veins (especially at node and near apex); air spaces in tissue; reproductive pouches 2, lateral, at base from which daughter fronds and flowers originate, triangular; veins 1–5(–7), originating from point in proximal part of frond (node) or if more than 3 veins present, outer ones sometimes branching distally from inner ones; scale at base of frond absent; anthocyanins sometimes present; pigment cells absent (red pigmentation present in some species); turions absent (sometimes present in <i>L. turionifera</i>). <b>Flowers</b> 1(–2) per frond, surrounded by small utricular, membranous scale; stamens 2, 4-locular. <b>Seeds</b> 1–5, longitudinally ribbed. <b>x</b> = 10, 21, 22</span><!-- -->{{Treatment/Body |distribution=Worldwide except arctic and antarctic regions. |discussion=<p>In <i>Lemna</i> the connection to the mother frond is formed by a thin white stipe at the base that falls off or decays after the frond is grown (frond of <i>L. trisulca</i> is narrowed at base into a green stalk persisting on frond).</p><!-- --><p>Species 13 (9 in the flora).</p> |tables= |references= }}<!-- --><div class="treatment-key"> ==Key== <div class="treatment-key-group"> {| class="wikitable fna-keytable" |-id=key-0-1 |1 |Fronds submersed (except when flowering or fruiting), margins denticulate distally, 2–3.5 times as long as wide, base suddenly narrowed into green stalk, 2–20 mm. |[[Lemna trisulca|Lemna trisulca]] |-id=key-0-1 |1 |Fronds floating, margins entire, 1–3 times as long as wide. |[[#key-0-2| > 2]] |-id=key-0-2 |2 |Fronds with 1 vein. |[[#key-0-3| > 3]] |-id=key-0-2 |2 |Fronds with 3–5(–7) veins. |[[#key-0-4| > 4]] |-id=key-0-3 |3 |Vein mostly prominent, longer than extension of air spaces, or running through at least 3/4 distance between node and apex |[[Lemna valdiviana|Lemna valdiviana]] |-id=key-0-3 |3 |Vein sometimes indistinct, very rarely longer than extension of air spaces, not longer than 2/3 distance between node and apex |[[Lemna minuta|Lemna minuta]] |-id=key-0-4 |4 |Root sheath winged at base; root tip usually sharp pointed; roots to 3(–3.5) cm; fronds without reddish color or spots of anthocyanin, mostly with 1 very distinct papilla near apex on upper surface. |[[#key-0-5| > 5]] |-id=key-0-4 |4 |Root sheath not winged; root tip mostly rounded; roots often longer than 3 cm; fronds often with reddish tinge or spots of anthocyanin, with or without distinct papilla near apex on upper surface. |[[#key-0-6| > 6]] |-id=key-0-5 |5 |Seeds with 35–70 indistinct ribs (to count ribs remove membranous pericarp), staying within fruit wall after ripening; root sheath wing 2–3 times as long as wide |[[Lemna perpusilla|Lemna perpusilla]] |-id=key-0-5 |5 |Seeds with 8–26 distinct ribs, falling out of fruit wall after ripening; root sheath wing 1–2.5 times as long as wide |[[Lemna aequinoctialis|Lemna aequinoctialis]] |-id=key-0-6 |6 |Plants forming small, olive to brown, rootless turions, which sink to bottom |[[Lemna turionifera|Lemna turionifera]] |-id=key-0-6 |6 |Plants usually without distinct turions. |[[#key-0-7| > 7]] |-id=key-0-7 |7 |Largest air spaces longer than 0.3 mm; if red-colored on lower surface, coloring beginning from margin; ovary (1–)2–7-ovulate |[[Lemna gibba|Lemna gibba]] |-id=key-0-7 |7 |Largest air spaces 0.3 mm or shorter; if pigmented on lower surface, red coloring beginning from attachment point of root; ovary 1-ovulate. |[[#key-0-8| > 8]] |-id=key-0-8 |8 |Fronds not reddish on lower surface (or at least much less so than on upper); greatest distance between lateral veins near or proximal to middle. |[[Lemna minor|Lemna minor]] |-id=key-0-8 |8 |Fronds often reddish on lower surface (more intensely so than on upper); greatest distance between lateral veins near or distal to middle. |[[#key-0-9| > 9]] |-id=key-0-9 |9 |Fronds flat, with mostly distinct papillae on midline of upper surface; seeds with 30–60 indistinct ribs |[[Lemna turionifera|Lemna turionifera]] |-id=key-0-9 |9 |Fronds often gibbous, with very distinct papillae above node and near apex on upper surface but not between node and apex; seeds with 10–16 distinct ribs |[[Lemna obscura|Lemna obscura]] |} </div></div><!-- -->{{#Taxon: name=Lemna |author= |authority=Linnaeus |rank=genus |parent rank=family |synonyms= |basionyms= |family=Lemnaceae |distribution=Worldwide except arctic and antarctic regions. |reference=None |publication title=Sp. Pl. |publication year=1754 |special status= |source xml=https://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/8f726806613d60c220dc4493de13607dd3150896/coarse_grained_fna_xml/V22/V22_243.xml |genus=Lemna }}<!-- -->[[Category:Treatment]][[Category:Lemnaceae]] Templates used on this page: Template:Lemnaceae (view source) Template:Treatment/AuthorLink (view source) Template:Treatment/Body (view source) Template:Treatment/Body/Maps (view source) Template:Treatment/ID (view source) Template:Treatment/Publication (view source) Return to Lemna.