View source for Trapa

{{Treatment/ID
|accepted_name=Trapa
|accepted_authority=Linnaeus
|publications={{Treatment/Publication
|title=Sp. Pl.
|place=1: 120. 1753
|year=1753
}}
|common_names=Water chestnut or caltrop;châtaigne d’eau
|basionyms=
|synonyms=
|hierarchy=Lythraceae;Trapa
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Lythraceae]]</div><div class="higher-taxon"><small>genus</small>[[Trapa]]</div></div>
|etymology=Greek kalkitrapa, ancient 4-spiked weapon, alluding to spiny fruit
|volume=Volume 10
|mention_page=
|treatment_page=
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--><span class="statement" id="st-d0_s0" data-properties="herb duration;herb growth form or habitat;herb growth form;herb architecture;herb growth form or location;herb some measurement;herb pubescence;herb pubescence"><b>Herbs,</b> annual, aquatic, rosette-forming, rooted or floating, to 50 dm (when rooted in deep water), glabrous or velutinous.</span> <span class="statement" id="st-d0_s1" data-properties="stem location;stem fragility;stem architecture;node location;node development;node coloration;node shape;node shape;node shape;root derivation;root architecture or shape"><b>Stems </b>submerged, flexible, unbranched, submerged nodes often developing green, pinnately-dissected to filiform adventitious leaflike roots.</span> <span class="statement" id="st-d0_s2" data-properties="leaf growth form;stipule architecture or shape"><b>Leaves </b>dimorphic, flanked by deeply cleft stipules;</span> <span class="statement" id="st-d0_s3" data-properties="leaf growth form or location;leaf arrangement;leaf shape;float architecture;float size;mid petiole architecture;mid petiole size;mid blade architecture;mid blade size;mid base architecture;mid base shape;mid base shape;mid base size;mid margin architecture;mid margin shape;mid margin shape;mid margin shape;mid margin size">floating leaves alternately or spirally arranged in terminal rosette, supported by slender to bulbous float at mid petiole, blade rhombic to triangular, base cuneate, margins coarsely toothed in distal 1/2;</span> <span class="statement" id="st-d0_s4" data-properties="leaf location;leaf arrangement;leaf architecture;blade arrangement or course or shape;margin architecture or shape">submerged leaves subopposite, sessile, blade linear, margins entire.</span> <span class="statement" id="st-d0_s5" data-properties="inflorescence development;inflorescence location;flower architecture or arrangement or growth form;leaf growth form or location;pedicel length;fruit development"><b>Inflorescences </b>indeterminate, emergent, solitary flowers in axils of floating leaves, pedicels elongating and declining after pollination, submerging developing fruit.</span> <span class="statement" id="st-d0_s6" data-properties="flower architecture;flower architecture"><b>Flowers </b>pedicellate, actinomorphic, monostylous;</span> <span class="statement" id="st-d0_s7" data-properties="floral-tube position;floral-tube position;floral-tube position;floral-tube shape">floral-tube perigynous to semi-epigynous, campanulate;</span> <span class="statement" id="st-d0_s8" data-properties="epicalyx segment presence">epicalyx segments absent;</span> <span class="statement" id="st-d0_s9" data-properties="sepal quantity;sepal length;sepal duration;spine texture">sepals 4, 3 times floral-tube length, persistent on fruit as hardened spines;</span> <span class="statement" id="st-d0_s10" data-properties="petal duration;petal quantity;petal coloration;petal coloration">petals caducous, 4, white or pale lavender;</span> <span class="statement" id="st-d0_s11" data-properties="">nectary development unknown;</span> <span class="statement" id="st-d0_s12" data-properties="stamen quantity;whorl quantity">stamens 4, in 1 whorl;</span> <span class="statement" id="st-d0_s13" data-properties="ovary architecture or structure in adjective form;ovary position;ovary position">ovary 2-locular, surrounded by coronary disc, semi-inferior, fully inferior in fruit;</span> <span class="statement" id="st-d0_s14" data-properties="placenta arrangement;placenta size">placenta axile, abbreviated, at apex of ovary;</span> <span class="statement" id="st-d0_s15" data-properties="style size">style slender;</span> <span class="statement" id="st-d0_s16" data-properties="stigma architecture or shape">stigma capitate;</span> <span class="statement" id="st-d0_s17" data-properties="ovule quantity;ovule orientation;ovule quantity">ovules 1 per locule, pendulous, 1 locule and ovule failing to develop after anthesis.</span> <span class="statement" id="st-d0_s18" data-properties="fruits drupe shape;fruits drupe texture;horn quantity;horn texture;horn architecture or shape;endocarp texture;exocarp duration"><b>Fruits </b>drupes, top-shaped, woody, with 2–4 hardened, spiny horns, endocarp indurate, exocarp evanescent, with tubercles.</span> <span class="statement" id="st-d0_s19" data-properties="seed quantity;seed shape"><b>Seed </b>1, oblong;</span> <span class="statement" id="st-d0_s20" data-properties="cotyledon quantity;cotyledon size;cotyledon quantity;cotyledon size;cotyledon texture;cotyledon nutrition;fruit apex shape">cotyledons 2, unequal, 1 large, starchy, retained in fruit, the other scalelike, growing out of fruit apex, becoming photosynthetic.</span><!--

-->{{Treatment/Body
|distribution=Europe;Asia;Africa;widely in subtropical and temperate regions
|introduced=true
|discussion=<p>Species 1–30+ (1 in the flora).</p><!--
--><p>Trapa is cultivated in China for the edible nut or enlarged cotyledon, which is referred to as water chestnut. The familiar cultivated Chinese water chestnut marketed in North America is usually another plant, the sedge Eleocharis dulcis (Burman f.) Trinius ex Henschel. Specialized features of Trapa (inflated leaf petioles, semi-inferior or fully inferior ovary, hardened horned fruits, unequal cotyledons) long made exact taxonomic placement difficult. Until recently, the genus was generally treated as the sole member of Trapaceae, with close relationship to Lythraceae or Onagraceae. Substantial molecular evidence indicates that Trapa is sister genus to Sonneratia Linnaeus f., a genus of mangrove trees in southeastern Asia. The two genera are well-nested within Lythraceae and closely related to two other Asian Lythraceae, Duabanga Buchanan-Hamilton, a genus of southeastern Asian trees, and Lagerstroemia, the crape myrtle (S. A. Graham et al. 2005). The great discrepancy in number of species attributed to the genus is primarily the result of extensive variability in the fruit shape and in the shape and number of horns and spines on the fruit. Trapa has become a notorious invader of rivers and lakes in the northeastern United States since its introduction in the nineteenth century. It was reported in southeastern Canada for the first time in 1998, extending the range northward from localities in the Lake Champlain watershed in the United States. Trapa fruits are well known from the Miocene, and younger, fossil deposits in the United States, Europe, and Asia.</p>
|tables=
|references=
}}<!--

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-->{{#Taxon:
name=Trapa
|author=C. Barre Hellquist;Shirley A. Graham
|authority=Linnaeus
|rank=genus
|parent rank=family
|synonyms=
|basionyms=
|family=Lythraceae
|distribution=Europe;Asia;Africa;widely in subtropical and temperate regions
|introduced=true
|reference=None
|publication title=Sp. Pl.
|publication year=1753
|special status=
|source xml=
|genus=Trapa
|blade arrangement or course or shape=linear
|cotyledon nutrition=photosynthetic
|cotyledon quantity=1;2
|cotyledon size=large;unequal
|cotyledon texture=starchy
|endocarp texture=indurate
|epicalyx segment presence=absent
|exocarp duration=evanescent
|float architecture=bulbous
|float size=slender
|floral-tube position=perigynous;semi-epigynous
|floral-tube shape=campanulate
|flower architecture=actinomorphic;pedicellate
|flower architecture or arrangement or growth form=solitary
|fruit apex shape=scalelike
|fruit development=developing
|fruits drupe shape=top--shaped
|fruits drupe texture=woody
|herb architecture=rooted
|herb duration=annual
|herb growth form=rosette-forming
|herb growth form or habitat=aquatic
|herb growth form or location=floating
|herb pubescence=velutinous;glabrous
|herb some measurement=0dm;50dm
|horn architecture or shape=spiny
|horn quantity=2;4
|horn texture=hardened
|inflorescence development=indeterminate
|inflorescence location=emergent
|leaf architecture=sessile
|leaf arrangement=subopposite;arranged
|leaf growth form=dimorphic
|leaf growth form or location=floating;floating
|leaf location=submerged
|leaf shape=toothed
|margin architecture or shape=entire
|mid base architecture=bulbous
|mid base shape=triangular;rhombic
|mid base size=slender
|mid blade architecture=bulbous
|mid blade size=slender
|mid margin architecture=bulbous
|mid margin shape=cuneate;triangular;rhombic
|mid margin size=slender
|mid petiole architecture=bulbous
|mid petiole size=slender
|node coloration=green
|node development=developing
|node location=submerged
|node shape=pinnately-dissected;filiform
|ovary architecture or structure in adjective form=2-locular
|ovary position=inferior;semi-inferior
|ovule orientation=pendulous
|ovule quantity=1;1
|pedicel length=elongating
|petal coloration=pale lavender;white
|petal duration=caducous
|petal quantity=4
|placenta arrangement=axile
|placenta size=abbreviated
|root architecture or shape=leaflike
|root derivation=adventitious
|seed quantity=1
|seed shape=oblong
|sepal duration=persistent
|sepal length=3 times floral-tube length
|sepal quantity=4
|spine texture=hardened
|stamen quantity=4
|stem architecture=unbranched
|stem fragility=flexible
|stem location=submerged
|stigma architecture or shape=capitate
|stipule architecture or shape=cleft
|style size=slender
|whorl quantity=1
}}<!--

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