foc
《中国植物志》英文修订版
Flora of China
  FOC Vol.23 (2010)              | Family List  Hydrocharitaceae  PDF     |  eFloras.org Link Font:+ Big | - Small
   6. Hydrocharitaceae  
水鳖科   shui bie ke
  
Authors:Authors: Qingfeng Wang, Youhao Guo, Robert R. Haynes & C. Barre Hellquist

  

Herbs, annual or perennial, submerged or floating, aquatic, in fresh or brackish water or marine. Stems short or elongated, sometimes stoloniferous. Leaves radical or cauline, alternate, opposite, subopposite, whorled, or pseudowhorled, sessile or petiolate, usually sheathing at base. Flowers unisexual or bisexual, actinomorphic, enclosed in a bifid spathe or within 2 opposite spathal bracts, or rarely not spatulate; spathes sessile or pedunculate. Stamens 1 to many, occasionally some staminodal; anthers 1-4-thecous. Ovary inferior, 1-loculed; carpels 2-15, fused; ovules few to many, on parietal, sometimes intruding placentae; styles 2-5; stigmas usually bifid. Fruit a fleshy and berrylike capsule dehiscent or opening by decay of pericarp, or an achene (Najas). Seeds numerous, usually small, without endosperm; embryo straight.

Eighteen genera and ca. 120 species: widely distributed in tropical and subtropical regions of the world; 11 genera (one introduced) and 34 species (four endemic, one introduced) in China.

Wang Huiqin & Sun Xiangzhong. 1992. Hydrocharitaceae. In: Sun Xiangzhong, ed., Fl. Reipubl. Popularis Sin. 8: 151-190; Zhou Lingyun, You Jun & Zhong Xiongwen. 1992. Najas. In: Sun Xiangzhong, ed., Fl. Reipubl. Popularis Sin. 8: 108-125.

Wang Huiqin & Sun Xiangzhong. 1992. Hydrocharitaceae. In: Sun Xiangzhong, ed., Fl. Reipubl. Popularis Sin. 8: 151-190; Zhou Lingyun, You Jun & Zhong Xiongwen. 1992. Najas. In: Sun Xiangzhong, ed., Fl. Reipubl. Popularis Sin. 8: 108-125.

  
1Fruit an elliptic-oblong achene; perianth 2-lipped; plant annual, submerged in fresh or brackish water; leaves sessile.1  Najas    茨藻属
+Fruit a fleshy and berrylike capsule; perianth segments free, 1- or 2-seriate, 3 per series, outer often sepaloid, inner petaloid; plant perennial or annual, floating or submerged; leaves petiolate or sessile(2)
   
2(1)Marine herbs; pollen grains threadlike(3)
+Freshwater herbs; pollen grains not threadlike(5)
   
3(2)Plants slender; leaves usually opposite or binate, not in 2 rows, linear to ovate, usually petiolate.10  Halophila    喜盐草属
+Plants robust; leaves alternate, in 2 rows, ribbonlike, sessile(4)
   
4(3)Female inflorescence shortly pedunculate; leaves smaller, slightly falcate.5  Thalassia    泰来藻属
+Female inflorescence long pedunculate; leaves larger, not falcate.4  Enhalus    海菖蒲属
   
5(2)Leaves all basal; stems short(6)
+Leaves cauline; stems elongated(9)
   
6(5)Leaves linear, ribbonlike, sessile; fruit narrowly cylindric(7)
+Leaves lanceolate to orbicular, usually petiolate(8)
   
7(6)Stamens 3-9; ovary attenuate into a long, filiform beak; peduncle of female flower shorter.6  Blyxa    水筛属
+Stamens 1-3; ovary not as above; peduncle of female flower very long.7  Vallisneria    苦草属
   
8(6)Stolon absent; leaves submerged; spathes usually winged.2  Ottelia    海菜花属
+Stolon present; leaves floating; spathes not winged.3  Hydrocharis    水鳖属
   
9(5)Leaves whorled(10)
+Leaves alternate, opposite, or spirally arranged(11)
   
10(9)Leaves distinctly serrate to unaided eye.9  Hydrilla    黑藻属
+Leaves minutely serrate, magnification needed.11  Egeria    水蕴草属
   
11(9)Flowers usually bisexual; sepals linear to lanceolate, shorter than petals; leaves with prominent midvein.6  Blyxa    水筛属
+Flowers unisexual; sepals ovate, subequal to petals; leaves lacking a prominent midvein.8  Nechamandra    虾子草属
   
   List of lower taxa