Potamogeton berchtoldii
From Wikipedia, the free encyclopedia
| Potamogeton berchtoldii | |
|---|---|
 | |
| Shoots of P. berchtoldii growing with milfoil and water crowfoot in a pond | |
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Monocots |
| Order: | Alismatales |
| Family: | Potamogetonaceae |
| Genus: | Potamogeton |
| Species: | P. berchtoldii |
| Binomial name | |
| Potamogeton berchtoldii Fieber [1] | |
| Synonyms | |
|
Potamogeton fieberi Rouy Potamogeton groenlandicus Hagstr. Potamogeton lacunatus Hagstr. | |
Potamogeton berchtoldii, common name small pondweed,[2] is an aquatic plant.
Small pondweed is a fine-leaved pondweeds with a bushy habit. It lacks a perennial rhizome and the plants die back in winter into a large number of resting buds known as turions. The stems are very slender and do not usually exceed 60 cm.[2] The leaves are flat, usually 25–50 mm long, and less than 2 mm wide, usually with a broad band of lacunae along each side of the midrib and coloured pale green, olive green or brownish green.[2] The open stipules and shining nodal glands can be important characters in identification.
Small pondweed is similar to several other Potamogeton species, especially P. pusillus, and use of a good key such as Preston (1995) is strongly recommended. It could also be confused with P. trichoides and P. obtusifolius.
Taxonomy
Small pondweed was first named by the German botanist Franz Xaver Fieber in 1838.[3] It is named after the 19th century Czech botanist Friedrich von Berchtold.[4]
This is one of a group of rather similar fine-leaved species that also includes P. pusillus, P. hillii and P. ochreatus.[5] Some authors consider it a form of P. pusillus.[6]
Subspecies include:[7]
- Potamogeton berchtoldii subsp. berchtoldii
- Potamogeton berchtoldii subsp. clystocarpus (Fernald) Les & Tippery – treated by some as Potamogeton clystocarpus[8]
- Potamogeton berchtoldii subsp. gemmiparus (J.W.Robbins) Les & Tippery
Hybrids have been described with P. trichoides (P. × franconicus G.Fisch.), P. pusillus (P. × mucronulatus (G.Fisch.) Papch.), P. natans, P. polygonifolius, P. coloratus (P. × lanceolatus Sm.), P. perfoliatus (P. × mysticus Morong), P. natans (P. × variifolius Thore), and P. acutifolius (P. × sudermanicus Hagstr.), but all are rare.[2][3]
Distribution
Potamogeton berchtoldii is native to Europe (including Britain, Ireland, continental Europe, Scandinavia), the Middle East, North America (Canada, US), Asia (Bhutan, China, Japan, Kazakhstan, Korea, Tajikistan, Turkmenistan, Russia, Uzbekistan), Asia Minor and the Middle East (Iraq, Iran, Turkey).[1][9][10]
