茨藻科 ci zao ke
Guo Youhao (郭友好)[1]; Robert R. Haynes[2], C. Barre Hellquist[3]
Herbs, annual, small, submerged in fresh or brackish water. Stem slender, fragile, much branched, rooting at base and lowermost nodes. Leaves subopposite or pseudowhorled, sessile, linear, small, 1-veined, sheathing at base, margin spinulose-toothed; sheaths variously shaped, often auriculate. Plants monoecious or dioecious; flowers minute, unisexual, solitary or few in leaf axil. Male flowers spatulate or rarely not spatulate; perianth (often named “involucre” or “envelope”) 1, 2-lipped, membranous, closely applied to anther; stamen 1, anther subsessile, 1–4-thecous, dehiscing at apex. Female flowers sessile; spathe absent or rarely present; perianth persistent. Fruit an elliptic-oblong achene; pericarp thin, membranous, indehiscent, persistent. Seeds without endosperm; testa hard, brittle, pitted; embryo straight.
One genus and ca. 40 species: cosmopolitan; nine species in China.
This family is [??generally] now merged with and included within Hydrocharitaceae. Najas marina subsp. intermedia (Wolfgang ex Gorski) Casper, N. pseudograminea W. Koch, and N. pseudogracillima L. Triest have been reported from China by Triest.
茨藻属 ci zao shu
Description and distribution as for the family.
1a. Plants dioecious; stems and abaxial surface of leaves usually spiny; areoles on seeds irregularly arranged 1. N. marina
1b. Plants monoecious; stems and abaxial surface of leaves usually not spiny; areoles on seeds longitudinally arranged.
2a. Anthers 1-thecous.
3a. Seeds with many transversely elongated ladderlike pits; areoles fusiform; fruit narrowed and slightly curved at apex ........................................................................................... 2. N. minor
3b. Seeds with many longitudinally elongated pits; areoles rectangular or polygonal; fruit usually straight.
4a. Auricles rounded or obcordate; leaves in pseudowhorls of 5 .............. 3. N. gracillima
4b. Auricles broadly triangular; leaves in pseudowhorls of 3 ................... 4. N. browniana
2b. Anthers 4(or rarely 2)-thecous.
5a. Male flowers without spathe; auricles narrowly triangular
or lanceolate
............................................................................................................ 9.
N. graminea
5b. Male flowers with spathe; auricles rounded or obcordate.
6a. Fruit semilunate; female flowers with a spathe ........................... 5. N. ancistrocarpa
6b. Fruit narrowly elliptic; female flowers without spathe.
7a. Areoles hexangular, transversely elongated, arranged in
ladderlike manner
................................................................................................ 6.
N. oguraensis
7b. Areoles rectangular or irregularly arranged.
8a. Auricles orbicular; testa with apparently raised cell walls ......... 7.. N. orientalis
8b. Auricles obcordate; testa without raised cell walls .................... 8. N. foveolata
大茨藻 da ci zao
Stems 30–100 cm or more tall, 1–4.5 mm in diam., mostly armed with spines, spines sometimes absent except apically. Leaves 1.5–3 cm × 2–3.5 mm, fleshy, abaxial side of midvein usually with spines; sheath ca. 3 mm, entire or serrulate with 1–3 spine cells on upper side without auricle, leaf with 2–10 conspicuous teeth on each side of margin; teeth 1–2 mm; apex acute. Plants dioecious. Flowers yellowish green. Male flowers ca. 5 × 2 mm; spathe with a short neck; anther 4-thecous. Female flowers 2–4.5 mm; style ca. 1 mm; stigmas 2- or 3-lobed. Fruit elliptic to obovoid-elliptic, 4–6 × 3–4 mm. Seeds ovoid; testa pitted; areoles polygonal, irregularly arranged. Fl. and fr. Sep–Nov. 2n=12*, 24, 48, 60*.
Ponds, lakes, slow-moving rivers; up to 2700 m. Anhui, Guangdong, Guangxi, Hebei, Heilongjiang, Henan, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Liaoning, Nei Mongol, Shandong, Shanxi, Taiwan, Xinjiang, Yunnan, Zhejiang [India, Japan, Korea, Malaysia, Mongolia, Myanmar, Pakistan, Russia, Sri Lanka, Tajikistan; Africa, Australia, Europe, North and South America].
1a.. Stems without spines except at apex; abaxial side of midvein without spines 1c. var. brachycarpa
1b.. Stems with spines; abaxial side of midvein with spines.
2a.. Margins of leaves with 4–10 conspicuous teeth; stems with spines ................ 1a. var. marina
2b.. Margins of leaves with 2 or 4 teeth; stems with only 1 or 2 spines under nodes 1b. var. grossedentata
大茨藻 (原变种) da ci zao (yuan bian zhong)
Ittnera major (Allioni) C. C. Gmelin; Najas marina var. angustifolia A. Braun.
Stems mostly armed with spines. Leaves with 4–10 conspicuous teeth on margin, abaxial side of midvein with spines ca. 2 mm.
Ponds, lakes, slow-moving rivers; up to 2700 m. Anhui, Guangdong, Guangxi, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, Nei Mongol, Shandong, Shanxi, Taiwan, Xinjiang, Yunnan, Zhejiang [India, Japan, Korea, Malaysia, Russia, Tajikistan; Africa, Australia, Europe, North America].
粗齿大茨藻 cu chi da ci zao
Stems stout, with only 1 or 2 spines under nodes. Margins of leaves with 2 or 4 teeth, abaxial side of midvein with sparse spines.
Ponds, lakes. Heilongjiang, Jilin, Liaoning [Korea].
短果茨藻 DUAN GUO CI ZAO
Najas intramongolica Y. C. Ma; N. marina subsp. brachycarpa (Trautvetter) Tzvelev.
Stems slightly slender, with spines only at top. Leaves smaller, abaxial side of midvein without spines.
Ponds. Nei Mongol, Xinjiang [C Asia].
小茨藻 xiao ci zao
Najas moshanensis N. Z. Wang.
Stems 4–25 cm tall, 0.5–1 mm in diam. Leaves recurved, 1–3 cm × 0.5–1 mm; sheath ca. 2 mm; auricles truncate to rounded, with more than 10 teeth on upper and outer sides of leaf margin, each side serrulate with 6–12 teeth, apex acuminate. Plants monoecious; flowers yellowish green. Male flowers elliptic, 0.5–1.5 mm; spathe with a short neck, with brownish spine cells at apex; anther 1-thecous. Female flowers ca. 2 mm; style 1–1.7 mm; stigmas 2-lobed. Fruit linear-ellipsoid, 2–3 × ca. 0.5 mm, narrowed and slightly curved at apex. Seeds narrowly ellipsoid, with many rows of transversely elongated ladderlike pits; areoles fusiform. Fl. and fr. Jun–Oct. 2n=12*, 24*, 36, 46, 56.
Ponds, lakes, paddy fields and channels; up to ca. 2700 m. Anhui, Fujian, Guangdong, Guangxi, Hainan, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, Nei Mongol, Shandong, Taiwan, Xinjiang, Yunnan, Zhejiang [India, Indonesia (Java), Japan including Ryukyus, Nepal, Pakistan, Philippines, Thailand; throughout Old World, Africa, Europe, introduced into North America].
纤细茨藻 xian xi ci zao
Najas indica (Willdenow) Chamisso var. gracillima A. Braun ex Engelmann in A. Gray, Man. Bot. 681. 1868; 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 waters of ponds and channels; up to ca. 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 the latter species in having fruit often straight and the areoles of its seeds are longer than broad.
高雄茨藻 gao xiong ci zao
Stems 20–30 cm tall, ca. 1 mm in diam. Leaves often in pseudowhorls of 3, linear, 1–2 cm × 0.5–1 mm; sheath shortly auriculate; auricles triangular, ca. 2 mm, minutely serrulate with several teeth on apex; leaf margin on each side minutely serrulate with 10–20 teeth. Plants monoecious; flowers solitary or 2 or 3 together. Male flowers ca. 1 mm; spathe with a short neck, with brownish spine cells at apex; anther 1-thecous. Female flowers linear-ellipsoid, ca. 1 mm; style short; stigmas 2-lobed. Fruit linear-ellipsoid, 1.5–1.7 mm. Seeds narrowly ellipsoid, with many rows of pits; areoles squarish to pentangular. Fl. and fr. Aug–Nov. 2n=12*.
In brackish waters. Guangdong, Guangxi, Taiwan [Indonesia, New Guinea; Australia].
According to Triest, Najas browniana is found only in Australia.
弯果茨藻 wan guo ci zao
Najas poyangensis S. F. Guan & Q. Lang.
Stems 10–30 cm tall, 0.5–1 mm in diam. Leaves narrowly linear or linear, 1–2 cm × ca. 0.5 mm; sheath 1–1.5 mm; auricles rounded, minutely serrulate with 5–8 teeth on upper side, margin each side minutely serrulate with 4–16 (or more) spiny teeth. Plants monoecious; flowers solitary. Male flowers 0.5–1.5 mm; spathe with a short neck, with 4 or 5 brownish spine cells at apex; anther 4-thecous. Female flowers recurved, with a spathe; neck of spathe with brownish spine cells at apex; style ca. 0.5 mm; stigmas 2-lobed. Fruit semilunate, 1–2 × ca. 0.5 mm. Seeds curved, fusiform, with many rows of pits; areoles oblong. Fl. and fr. Jul–Oct. 2n=12*, 24.
Still water. Fujian, Hubei, Jiangxi, Taiwan, Zhejiang [Japan]
澳古茨藻 ao gu ci zao
Stems 20–30 cm tall, 1–2.5 mm in diam. Leaves narrowly linear to subulate, 1–2 cm × 1–3 mm, slightly curved; midvein sometimes with spines; sheath 3–5 mm; auricles orbicular to obcordate, short, minutely serrulate with several teeth at apex; leaf margin on each side serrulate with 7–14 teeth. Plants monoecious; flowers solitary. Male flowers usually in upper axils, female ones throughout; male flowers elliptic, ca. 1 mm; spathe with a neck, with several brownish spine cells at apex; anther 4-thecous; female flowers ca. 3 mm; style ca. 0.5 mm; stigmas 2-lobed. Fruit narrowly ellipsoid, 3–4 × ca. 1 mm, narrowed and curved at apex. Seeds narrowly ellipsoid, with many rows of transversely elongated ladderlike pits; areoles hexangular. Fl. and fr. Jul–Nov. 2n=24, 60*.
Still water. Hubei, Jiangxi, Taiwan [India, Japan, ?Nepal, Pakistan].
东方茨藻 dong fang ci zao
Najas chinensis N. Z. Wang.
Stems 10–15 cm tall, 0.5–1 mm in diam. Leaves linear to narrowly lanceolate, 1–3 cm × 0.2–1 mm; sheath ca. 2 mm; auricles rounded, minutely serrulate with several teeth on each side, leaf margin on each side minutely serrulate with 6–20 teeth. Plants monoecious; flowers solitary or sometimes 2 together, male flowers in upper axils and female ones throughout. Male flowers elliptic, ca. 1 mm; spathe with a neck, with several brownish spine cells at apex; anther 4-thecous. Female flowers 2–2.5 mm; style ca. 1 mm; stigmas 2–4(or 5)-lobed. Fruit narrowly ellipsoid, 2–2.5 × ca. 0.5 mm. Seeds slightly reniform, with ca. 20 rows of pits; areoles regularly arranged, nearly square; cell walls apparently raised. Fl. and fr. May–Aug. 2n=12*.
Ponds, channels, paddy fields, slow-moving rivers; up to ca. 1800 m. Fujian, Guangdong, Guangxi, Hainan, Hubei, Jiangxi, Jilin, Liaonong, Taiwan, Yunnan, Zhejiang [Japan; Europe].
Najas orientalis is similar to N. foveolata, but the former can be easily separated from the latter by its rounded sheath and apparently raised cell walls of the seed coat.
多孔茨藻 duo kong ci zao
Stems 10–20 cm tall, 0.5–1 mm in diam. Leaves linear, slender, 2–2.5 cm × 0.2–0.5 mm; sheath 2–2.5 mm; auricles obcordate; minutely serrulate with 4–9 teeth at apex and outer side; leaf margin on each side minutely serrulate with 6–24 teeth. Plants monoecious; flowers solitary, male flowers in upper axils and female flowers throughout. Male flowers elliptic ca. 1 mm; spathe with a short neck, with several browish spine cells at apex; anther 4-thecous; female flowers ca. 2.5 mm; style ca. 1 mm; stigmas 2-lobed, unequal. Fruit narrowly ellipsoid, ca. 1.5 × 0.5 mm. Seeds narrowly ellipsoid, with ca. 20 rows of pits; areoles nearly squarish to polygonal. Fl. and fr. Aug–Sep. 2n=12*, 24, 36.
Ponds. Anhui, Guangxi, Hubei, Taiwan, Zhejiang [India, Malaysia].
Previously, this species was only known from S Guangxi.
草茨藻 cao ci zao
Stems 10–20 cm tall, 0.5–1 mm in diam. Leaves narrowly linear to linear, 1–2.5 cm × 0.4–1 mm; sheath 1.5–3 mm, deeply auriculate; auricles narrowly triangular or lanceolate, 1–2 mm, serrulate with several teeth on each side, apex acute; leaf margin on each side minutely and densely serrulate with 30–50 inconspicuous teeth, consisting of brownish spine cells only. Plants monoecious; flowers solitary, or sometimes 2 or 3 together. Male flowers usually more toward upper axils, ca. 1 mm, elliptic; spathe absent; anther 4-thecous. Female flowers 1.5–2 mm; style ca. 1 mm; stigmas 2–4-lobed. Fruit oblong, 1.5–2 × ca. 0.8 mm. Seeds ellipsoid-oblong, with ca. 30 rows of pits; areoles hexangular and irregularly polygonal toward the ends, or rectangular. Fl. and fr. Jun–Sep. 2n=12*, 24, 36*, 48, 72.
Ponds, paddy fields, usually in still or slow-moving waters; up to ca. 1800 m. Anhui, Fujian, Guangdong, Guangxi, Hainan, Hebei, Henan, Hubei, Jiangsu, Liaoning, Sichuan, Taiwan, Yunnan, Zhejiang [Bangladesh, India, ??Indonesia, Japan including Ryukyus, Korea, Malaysia, Myanmar, Nepal, Phillipines, Sri Lanka, Thailand; throughout Old World, Africa, Australia, introduced into North America].
1a.. Fruit not curved; areoles hexangular to polygonal ........................................... 9a. var. graminea
1b.. Fruit curved toward apex; areoles oblong ...................................................... 9b. var. recurvata
草茨藻 (原变种) cao ci zao (yuan bian zhong)
Leaves ca. 1 mm wide; auricles narrowly triangular. Fruit usually straight. Seeds with hexangular or irregularly polygonal areoles.
Ponds, paddy fields, usually in still or slow-moving waters. Anhui, Fujian, Guangdong, Guangxi, Hainan, Hebei, Henan, Hubei, Jiangsu, Liaoning, Taiwan, Yunnan [India, ??Indonesia, Japan including Ryukyus, Korea, Malaysia, Myanmar, Phillipines [Africa, Australia, Europe, introduced into North America].
弯果草茨藻 wan guo cao ci zao
Leaves less than 0.5 mm wide; auricles shortly lanceolate. Fruit recurved at apex. Seeds with apparently oblong areoles.
* Paddy fields. Hubei, Zhejiang.
[1] Herbarium or Wuhan University, Department of Biology, Wuchang, Hubei, People’s Republic of China
[2] Herbarium, Biological Sciences, Biodiversity and Systematics Department, University of Alabama, Box 870345, Tuscaloosa, Alabama 35487-0345, U.S.A.
[3] Department of Biology, Massachusetts College of Liberal Arts, North Adams, Massachusetts 01247-4100, U.S.A.