大叶藻科 DA YE ZAO KE
Guo Youhao(郭友好)[1], Robert R. Haynes[2], C. Barre Hellquist[3]
Herbs perennial, rarely annual, of saline water, rhizomatous, caulescent. Leaves alternate, submersed, sessile, sheath persisting longer than blade or decaying into bundles of fibers, blade linear. Inflorescences axillary or terminal, spadices surrounded by spathe, pedunculate. Flowers unisexual, staminate and pistillate on same plant or separate plants; subtending bracts often present; perianth lacking. Staminate flowers with single stamen, anthers dehising longitudinally. Pistillate flowers with single pistil. Fruit achene-like, seeds 1 with straight embryo.
1a. Plants monoecious; fruit usually ovoid .................................................................... 1. Zostera
1b. Plants dioecious; fruit usually curved ............................................................. 2. Phyllospadix
大叶藻属 da ye zao shu
Rhizome monopodial, with 2 vascular bundles in cortex. Shoots short, with several leaves; flowering stems usually elongated, with several spathes. Leaves linear, with 3–11 parallel veins, margin entire or rarely minutely denticulate; sheaths membranous or nearly leathery, with an auricle, ligulate. Spadix axillary, sessile, axis flattened, without or only with inconspicuous projections (retinacula). Plants monoecious; flowers unisexual, small. Anthers 2-celled. Style short; stigmas 2, filiform or subulate. Fruit ovoid, with a short beak.
About 12 species: best represented along shores of north temperate regions; five species in China.
1a. Leaves 3-veined; sheaths open; projections present on each side of spadix axil ... 5. Z. japonica
1b. Leaves 5–11-veined; sheaths closed; projection usually absent.
2a. Rhizomes slightly erect, with very short internodes; sheaths slightly leathery, persistent; leaf apex retuse 2. Z. caespitosa
2b. Rhizomes creeping, internodes elongated; sheaths usually membranous, not persistent; leaf apex obtuse or mucronate, rarely retuse.
3a. Seeds longitudinally ribbed; leaves 5–7-veined ............................................ 1. Z. marina
3b. Seeds smooth on surface; leaves 5–11-veined.
4a. Leaves 5–8 mm wide, apex obtuse or mucronate; fruit ca. 4 mm ...... 3. Z. caulescens
4b. Leaves 1–1.5 cm wide, apex
truncate or retuse; fruit 5–6.5 mm
.......................................................................................................... 4.
Z. asiatica
大叶藻 da ye zao
Rhizomes creeping, 2–4 mm in diam., with elongated internodes. Leaves on non-flowering shoots 5–8, linear, longer than 50 cm, 3–6 mm wide, 5–7-veined, margin entire, apex rounded or mucronate; sheaths closed, tubular, membranous, splitting irregularly when old; auricle ca. 1 mm; ligule ca. 0.5 mm; intravaginal squamules 2 or 4, linear. Flowering stems ca. 1 m, branched; spathes with flattened stalk, narrower than leaves; spadix without projections (retinacula). Anthers 4–5 mm. Ovary 2–3 mm; style 1.5–2.5 mm; stigmas ca. 3 mm in length. Fruit ellipsoid, ca. 4 mm. Seeds longitudinally ribbed. Fl. and fr. Mar–Jul. 2n=12.
On fine gravel, sand, or mud near low tide mark. Coasts of Hebei, Liaoning, Shandong [Coasts of Japan, Korea, Russia; N Africa, Europe, North America].
丛生大叶藻 cong sheng da ye zao
Rhizomes slightly erect, with very short internodes. Leaves on non-flowering shoots 3 or 4, linear, ca. 60 cm × 3–6 mm, 5–7-veined, margin entire or sometimes minutely denticulate, apex retuse; sheaths closed, tubular, slightly leathery, persistent, splitting irregularly when old; auricle ca. 1 mm; ligule ca. 0.5 mm; intravaginal squamules 2, linear. Flowering stems 30–60 cm, branched; spathes with flattened stalk, narrower than leaves; spadix without projections. Anthers 4–5 mm. Ovary ca. 2.5 mm; style ca. 2 mm; stigmas subulate, ca. 2 mm. Fruit ellipsoid, ca. 3.5 mm. Seeds with 16–20 longitudinally ribs. Fl. and fr. Apr–Jun. 2n = 12.
Bottoms of shallow seas. Coast of Liaoning (Dalian) [Coasts of Japan and Korea].
具茎大叶藻 ju jing da ye zao
Rhizomes creeping, 2–3.5 mm in diam., internodes 1–2 cm. Leaves on non-flowering shoots several, linear, ca. 50 cm × 5–8 mm, 5–9-veined, margin entire, apex obtuse or mucronate; sheaths closed, tubular, membranous, splitting irregularly when old; auricle ca. 2 mm; ligule 1–1.5 mm; intravaginal squamules 2, linear. Flowering stems ca. 1 m, branched, usually lower branches with spathes, upper ones with leaves; spathes with flattened stalk, narrower than leaves; spadix without projections. Anthers 4.5–6 mm. Ovary ca. 2 mm; style ca. 2 mm; stigmas 2.5–3 mm. Fruit narrowly ellipsoid, ca. 4 mm. Seeds slightly smooth. Fl. and fr. Apr–Jun. 2n=12.
Bottoms of shallow seas. Coast of Liaoning [Coasts of Japan and Korea].
宽叶大叶藻 kuan ye da ye zao
Rhizomes creeping, internodes 1–2 cm. Leaves on non-flowering shoots several, linear, ca. 1 m × 1–1.5 cm, 7–11-veined, apex truncate or obtuse; sheaths closed, tubular, membranous, splitting irregularly when old; auricle obtuse; ligule very short; intravaginal squamules 2, linear. Flowering stems ca. 1 m, branched; spathes with flattened stalk, narrower than leaves, apex retuse; spadix without projections. Anthers ca. 4 mm. Ovary 2–3 mm; style 1–1.5 mm; stigmas ca. 2.5 mm. Fruit narrowly ellipsoid, 5–6.5 mm. Seeds smooth. Fl. and fr. Jul–Mar. 2n=12.
Bottoms of shallow seas. Rarely along coasts of Liaoning [Coasts of Japan, Korea, and E Russia].
矮大叶藻 ai da ye zao
Nanozostera japonica (Ascherson & Graebner) Tomlinson & Posluzny.
Rhizomes creeping, 0.5–1.5 mm in diam., internodes 0.5–3 cm. Leaves on non-flowering shoots 2–4, linear, 5–35 × 1–2 mm, 3-veined, apex obtuse or retuse; sheaths open, 2–10 cm, margin membranous; auricle obtuse, ca. 0.5 mm; intravaginal squamules 2, lanceolate. Flowering stems 10–30 cm; spathes with flattened stalk, ca. as broad as or narrower than leaves, apex obtuse, mucronate, rarely retuse; spadix with projections. Anthers ca. 2 mm. Ovary ca. as long as style; stigmas subulate. Fruit ellipsoid to narrowly cylindric, ca. 2 mm. Seeds smooth. Fl. and fr. Jun–Sep. 2n=12.
Bottoms of shallow seas. Coasts of Hebei, Liaoning, Shandong, Taiwan [Coasts of Japan, Korea, and E Russia; Africa, Asia, Europe, North America].
虾海藻属 xia hai zao shu
Rhizome monopodial, with 2 vascular bundles in cortex. Erect stems absent or strongly abbreviated, with dense, persistent fibrous leaf bases. Leaves linear, usually leathery, with 3–7 parallel veins, margin irregularly minutely denticulate; sheaths with an auricle, ligulate. Spadix axillary, sessile, axis flattened, with a row of conspicuous flaplike projections (retinacula) on each side of axis. Plants dioecious; flowers unisexual, small; anthers 2-celled. Female flowers consist of one carpel, often with staminode; style short; stigmas 2, capillary. Fruit curved, with a short beak.
About five species: widely distributed along shores of the north Pacific Ocean; two species in China.
1a. Leaves 1.5–2.5 mm wide, apex usually retuse, 3-veined; persistent fibrous leaf bases blackish brown 1. P. japonica
1b. Leaves 2–4.5 mm wide, apex obtuse, 5-veined (rarely 3-veined); persistent fibrous leaf bases reddish brown 2. P. iwatensis
黑纤维虾海藻 hei xian wei xia hai zao
Rhizomes creeping, 3–4 mm in diam. Stems abbreviated, internodes 3–5 mm; persistent fibrous leaf bases blackish brown. Leaves alternate; leaf blade linear, 25–100 cm × 1–2.5 mm, 3-veined, margin entire or irregularly denticulate toward apex, apex obtuse and retuse; sheaths 4–20 cm, amplexicaul. Spathe 1, with flattened stalk 1–3(–7.5) cm and shrimplike sheath; projections ovate-lanceolate, alternate with flowers. Anthers with 2 filiform theca. Carpels sagittate to cordate at base. Fruit 2–2.5 × 4–5 mm, semilunate; beak apical. Fl. and fr. Mar–Aug. 2n=16, 20.
Fine gravel or sand near low tide mark; sea level up to ca. 8 m. Coasts of Hebei, Liaoning, Shandong [Coasts of Japan, Korea, E Russia].
红纤维虾海藻 hong xian wei xia hai zao
Rhizomes creeping, ca. 5 mm in diam. Stems abbreviated, internodes 4–5 mm; persistent fibrous leaf bases reddish brown. Leaves alternate, linear, 1–1.5 m × 2–4.5 mm, 5-veined, rarely 3-veined, margin entire basally, but irregularly denticulate toward apex, apex obtuse; sheaths ca. 25 cm, amplexicaul. Spathe 1, with flattened stalk 1.2–5(–8) cm and shrimplike sheath; projections obliquely ovate to lanceolate, alternate with flowers. Anthers with 2 filiform theca. Carpels sagittate at base. Fruit compressed, 2.2–3 × 4–5 mm, semilunate; beak apical. Fl. and fr. Apr–Oct. 2n=16, 20.
Fine gravel or sand near low tide mark; sea level up to ca. 8 m. Coasts of Hebei, Liaoning, Shandong [Coasts of Japan and Korea].
[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.