Najas gracillima is most similar to N. minor, especially in vegetative condition. Najas gracillima, however, can be separated from the latter species by its style arising off-center at the apex of the ovary wall and by its aeroleareoles being longer than broad. Late in the growing season, the leaves of N. minor become recurved; those of N. gracillima do not.
Najas gracillima,[2][3][4][5] the slender waternymph,[6] is a submerged species of aquatic plant in the Hydrocharitaceae family.[7] found in lakes and streams. It is native to China (Fujian, Guangxi, Guizhou, Hainan, Hebei, Hubei, Jiangxi, Jilin, Liaoning, Nei Mongol, Taiwan, Yunnan, Zhejiang), Russian Far East (Amur and Khabarovsk), Japan, Korea, Taiwan, Iran, Alberta, Ontario, Newfoundland, Nova Scotia, New Brunswick, the eastern United States (every state east of the Mississippi River except Florida, plus Minnesota, Iowa, Missouri and the District of Columbia). It is also considered introduced and naturalized in France, Spain, Italy and California (Plumas and Tehama Counties).[8][9][10][11]
Najas gracillima is a small aquatic annual with branching stems. The unisexual flowers ( each flower is only one sex) are produced in the axils of the branchlets and bases of the leaf sheaths.[12] It is listed as endangered in Minnesota.[12] It lives in soft-water lakes and ponds with mud and silt bottoms, and appears to be sensitive to water turbidity, warming, and eutrophication.[12]
Najas gracillima, the slender waternymph, is a submerged species of aquatic plant in the Hydrocharitaceae family. found in lakes and streams. It is native to China (Fujian, Guangxi, Guizhou, Hainan, Hebei, Hubei, Jiangxi, Jilin, Liaoning, Nei Mongol, Taiwan, Yunnan, Zhejiang), Russian Far East (Amur and Khabarovsk), Japan, Korea, Taiwan, Iran, Alberta, Ontario, Newfoundland, Nova Scotia, New Brunswick, the eastern United States (every state east of the Mississippi River except Florida, plus Minnesota, Iowa, Missouri and the District of Columbia). It is also considered introduced and naturalized in France, Spain, Italy and California (Plumas and Tehama Counties).
Najas gracillima is a small aquatic annual with branching stems. The unisexual flowers ( each flower is only one sex) are produced in the axils of the branchlets and bases of the leaf sheaths. It is listed as endangered in Minnesota. It lives in soft-water lakes and ponds with mud and silt bottoms, and appears to be sensitive to water turbidity, warming, and eutrophication.
Najas gracillima là một loài thực vật có hoa trong họ Hydrocharitaceae. Loài này được (A.Braun ex Engelm.) Magnus mô tả khoa học đầu tiên năm 1870.[1]
Najas gracillima là một loài thực vật có hoa trong họ Hydrocharitaceae. Loài này được (A.Braun ex Engelm.) Magnus mô tả khoa học đầu tiên năm 1870.
日本茨藻（学名：Najas gracillima）为茨藻科茨藻属下的一个种。
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保全状況評価 準絶滅危惧（環境省レッドリスト）
分類 界 : 植物界 Plantae 門 : 被子植物門 Magnoliophyta 綱 : 単子葉植物綱 Liliopsida 目 : オモダカ目 Alismatales 科 : トチカガミ科 Hydrocharitaceae 属 : イバラモ属 Najas 種 : イトトリゲモ N. gracillima 学名 Najas gracillimaNajas japonica
Nakai.
イトトリゲモ(Najas gracillima)は、トチカガミ科イバラモ属に属する水草。和名は、糸のように細い鳥の毛、という意である。
東アジアに生育するほか、イタリアでは外来種として生育している[1]。日本でも全国各地に分布している。ため池や水路、水田などで見られる[2]。
沈水性の一年草。全長は10-30cm[1]、鋸歯のある長さ1-2cmの線形葉を5輪生する[1]。花期は6-9月、葉腋に花をつけ、長さ約2mmの種子が2個並んで形成される[1]。雌雄同株[2]。
ホッスモやオオトリゲモに形態が似るが、イトトリゲモでは葉腋につく種子が2個並ぶという特徴があり、区別の指標となる[3]。ただし、ホッスモなどでも種子が2個並んでつくこともあり、より正確に同定するためには、種子表面の網目模様など他の形態も検討すべきである[1]。
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