纤细茨藻Najas gracillima (A. Br.) Magnus
纤细茨藻Najas gracillima (A. Br.) Magnus
3. 纤细茨藻（新拟）图版46
Najas gracillima (A. Br.) Magnus, Beitr. 23. 1870; Rendle in Trans. Linn. Soc. Lond. Bot. 5: 414. 1899, et in Engl. Pflanzenr. 7 (IV 12): 15. 1901; Miki in Bot. Mag. Tokyo 49 (587): 773. f. 6. 1935.——N. indica (Willd.) Cham. var. gracillima A. Br. ex Engelm. in A. Gray. Man. Bot. 681. 1868.——N. japonica Nakaiin Journ. Jap. Bot. 13: 853. 1937; Ohwi, Fl. Jap. 59. 1956; 台湾植物志5: 37. 1978; 中国水生高等植物图说216.图157. 1983.——N. graminea auct. non Del.: 东北植物检索表452. 图版167. 图3. 1959.
一年生沉水草本。植株纤细，易碎，呈黄绿色至深绿色，基部节生有不定根，株高10-20厘米。茎圆柱形，直径0.3-0.5毫米，少有更粗壮者，节间长1-2厘米；分枝多，呈二叉状。叶多为5叶假轮生，少数为3叶或，叶以上假轮生，多呈簇生的数枚叶与单枚叶拟对生状态，无柄；叶片狭线形至刚毛状，长约2厘米，宽约0.5毫米，下部几无齿，上部边缘每侧具极小的刺状细齿7-11枚，齿端具1黄褐色刺细胞；叶表皮细胞近长方形；叶鞘显著，长1-2毫米，黄绿色至褐色，抱茎，圆形至多少呈倒心形；叶耳短，先端具刺状细齿6-7枚。花单性，1-4朵腋生，2朵以上者多只有1朵雄花，其他皆为雌花；雄花椭圆形，黄绿色，花形较小而不易发现，具1佛焰苞和1花被；雄蕊1枚，花药1室；花粉粒椭圆形；雌花显著，裸露，每雌花具1雌蕊；花柱长1-2毫米，柱头2裂。瘦果褐色，长椭圆形，长约2毫米，直径约0.5毫米，常成对生于茎节上。种皮细胞20余列，呈长方形，轴向明显大于横向。花果期6-8月。2n=12。
产吉林、辽宁、内蒙古、台湾、浙江、湖北、福建、广西、海南、贵州和云南等省区。多生于稻田或藕田中，亦见于水沟和池塘的浅水处，海拔达1 800米（云南昆明）。也分布于日本和美洲等地。
本种与小茨藻相似，区别在于多5叶假轮生；果实直，长椭圆形，常成对出现。
《Flora of China》 Vol. 23 (2010)
Najas gracillima (A. Braun ex Engelmann) Magnus Beitr. Kenntn. Najas. 23. 1870.
纤细茨藻 xian xi ci zao
Najas indica (Willdenow) Chamisso var. gracillima A. Braun ex Engelmann in A. Gray, Manual, ed. 5, 681. 1867; N. japonica Nakai.
Stems 8-20 cm tall, 0.3-0.5 mm in diam. Leaves often in pseudowhorls of 5, ca. 2 cm × 0.3-0.5 mm; sheath 1-2 mm; auricles orbicular to slightly obcordate, short, minutely serrulate with 6 or 7 teeth, upper margin on each side minutely serrulate with 7-11 teeth. Plants monoecious; flowers 1-4 per axil, male flowers in upper axils and female ones throughout. Male flowers elliptic, 1-1.5 mm; spathe with a short neck, with brownish spine cells at apex; anther 1-thecous. Female flowers conspicuous, 2-3 mm; style 1-2 mm; stigmas 2-lobed. Fruit linear-ellipsoid, 2-3 × ca. 0.5 mm. Seeds narrowly ellipsoid, with more than 20 rows of pits; areoles oblong, longitudinally elongated. Fl. and fr. Jun-Aug. 2n = 12, 24.
Paddy fields, shallow water of ponds and channels; below 1800 m. Fujian, Guangxi, Guizhou, Hainan, Hebei, Hubei, Jiangxi, Jilin, Liaoning, Nei Mongol, Taiwan, Yunnan, Zhejiang [Japan; North America].
Najas gracillima is most similar to N. minor, especially in vegetative condition. However, N. gracillima can be separated from N. minor by its fruit often straight and the areoles of its seeds longer than broad.Najas gracillima is most similar to N. minor, especially in vegetative condition. However, N. gracillima can be separated from N. minor by its fruit often straight and the areoles of its seeds longer than broad.
别名：slender waternymph;淘木-疏得乐吉;细叶茨藻;丝叶茨藻;日本茨藻;茨藻;细茨藻;纤梗茨藻;
科名：茨藻科 Najadaceae
属名：茨藻属 Najas
3. 纤细茨藻（新拟）图版46
Najas gracillima (A. Br.) Magnus, Beitr. 23. 1870; Rendle in Trans. Linn. Soc. Lond. Bot. 5: 414. 1899, et in Engl. Pflanzenr. 7 (IV 12): 15. 1901; Miki in Bot. Mag. Tokyo 49 (587): 773. f. 6. 1935.——N. indica (Willd.) Cham. var. gracillima A. Br. ex Engelm. in A. Gray. Man. Bot. 681. 1868.——N. japonica Nakaiin Journ. Jap. Bot. 13: 853. 1937; Ohwi, Fl. Jap. 59. 1956; 台湾植物志5: 37. 1978; 中国水生高等植物图说216.图157. 1983.——N. graminea auct. non Del.: 东北植物检索表452. 图版167. 图3. 1959.
一年生沉水草本。植株纤细，易碎，呈黄绿色至深绿色，基部节生有不定根，株高10-20厘米。茎圆柱形，直径0.3-0.5毫米，少有更粗壮者，节间长1-2厘米；分枝多，呈二叉状。叶多为5叶假轮生，少数为3叶或，叶以上假轮生，多呈簇生的数枚叶与单枚叶拟对生状态，无柄；叶片狭线形至刚毛状，长约2厘米，宽约0.5毫米，下部几无齿，上部边缘每侧具极小的刺状细齿7-11枚，齿端具1黄褐色刺细胞；叶表皮细胞近长方形；叶鞘显著，长1-2毫米，黄绿色至褐色，抱茎，圆形至多少呈倒心形；叶耳短，先端具刺状细齿6-7枚。花单性，1-4朵腋生，2朵以上者多只有1朵雄花，其他皆为雌花；雄花椭圆形，黄绿色，花形较小而不易发现，具1佛焰苞和1花被；雄蕊1枚，花药1室；花粉粒椭圆形；雌花显著，裸露，每雌花具1雌蕊；花柱长1-2毫米，柱头2裂。瘦果褐色，长椭圆形，长约2毫米，直径约0.5毫米，常成对生于茎节上。种皮细胞20余列，呈长方形，轴向明显大于横向。花果期6-8月。2n=12。
产吉林、辽宁、内蒙古、台湾、浙江、湖北、福建、广西、海南、贵州和云南等省区。多生于稻田或藕田中，亦见于水沟和池塘的浅水处，海拔达1 800米（云南昆明）。也分布于日本和美洲等地。
本种与小茨藻相似，区别在于多5叶假轮生；果实直，长椭圆形，常成对出现。
《Flora of China》 Vol. 23 (2010)
Najas gracillima (A. Braun ex Engelmann) Magnus Beitr. Kenntn. Najas. 23. 1870.
纤细茨藻 xian xi ci zao
Najas indica (Willdenow) Chamisso var. gracillima A. Braun ex Engelmann in A. Gray, Manual, ed. 5, 681. 1867; N. japonica Nakai.
Stems 8-20 cm tall, 0.3-0.5 mm in diam. Leaves often in pseudowhorls of 5, ca. 2 cm × 0.3-0.5 mm; sheath 1-2 mm; auricles orbicular to slightly obcordate, short, minutely serrulate with 6 or 7 teeth, upper margin on each side minutely serrulate with 7-11 teeth. Plants monoecious; flowers 1-4 per axil, male flowers in upper axils and female ones throughout. Male flowers elliptic, 1-1.5 mm; spathe with a short neck, with brownish spine cells at apex; anther 1-thecous. Female flowers conspicuous, 2-3 mm; style 1-2 mm; stigmas 2-lobed. Fruit linear-ellipsoid, 2-3 × ca. 0.5 mm. Seeds narrowly ellipsoid, with more than 20 rows of pits; areoles oblong, longitudinally elongated. Fl. and fr. Jun-Aug. 2n = 12, 24.
Paddy fields, shallow water of ponds and channels; below 1800 m. Fujian, Guangxi, Guizhou, Hainan, Hebei, Hubei, Jiangxi, Jilin, Liaoning, Nei Mongol, Taiwan, Yunnan, Zhejiang [Japan; North America].
Najas gracillima is most similar to N. minor, especially in vegetative condition. However, N. gracillima can be separated from N. minor by its fruit often straight and the areoles of its seeds longer than broad.Najas gracillima is most similar to N. minor, especially in vegetative condition. However, N. gracillima can be separated from N. minor by its fruit often straight and the areoles of its seeds longer than broad.