Variation Patterns And Geographical Distribution Of Inflorescences And Fruits Of Sparganium Glomeratum Laest. Ex Beurl. (Sparganiaceae)

Sparganium glomeratum Laest. ex Beurl. belonging to the family Sparganiacea, is a perennial herb. They are mainly distributed in the northeastern and southwestern parts of China. We surveyed the 18 morphological characters of 19 S. glomeratum populations, especially studied the morphological characters of inflorescences and fruits, and analyzed the correlation between phenotypic variation and the geographical distribution.The results are mainly as follows:1. They are six types of the lowest peduncles of female of S. glomeratum, that is:1) The supra-axillary lowest peduncle to the last node, and connate; 2) The supra-axillary lowest peduncle to the last node, and apex free; 3) The supra-axillary lowest peduncle below the last node; 4) The supra-axillary lowest peduncle above the last node; 5) They are similar to the type 1, with 1 branch at base of inflorescence; 6) The supra-axillary lowest peduncle connect with the upper female head.2. They are two fruit types of S. glomeratum, that is:long and narrow type and constricted near the centre type, the type of constricted near the centre is the most common type.3. The perianth segments of S. glomeratum have morphological diversity. We found the fifteen tip types in perianth segments and nine margin types in perianth segments.4. We analyzed the 18 phenotypic characters of 19 S. glomeratum populations, the results show:the inflorescence in fruit diameter/raceme length, raceme length/height, raceme length, bract length are significant differences within the populations; And the height and leaf length or width are differences among the populations.5. We analyzed the correlation between phenotypic traits and the geographical factor (latitude and longitude), the results showed:the plants in the northeast are greater in plant height and bract width than those in the southwest.Besides, we observed and described the fruit morphological characters of nine species of Sparganium in China, presented the key to Sparganium by fruit morphological characters (color of perianth segments, stalk length).