Panarctic Flora

3309002 Carex lasiocarpa Ehrh.

2n= 56. - Europe, North America. - At least four reports. See note below.

Geography: Circumboreal: NOR RUS (CAN).

Notes: Hybrids are very frequent among species of sect. Vesicariae and are also found between these and species of sect. Paludosae. With some exceptions, the hybrids seem to be nearly or fully sterile with largely aborting anthers and pollen and very low or absent fruit-set. However, as all species are rhizomatous, the hybrids may form extensive clones durating for a very long time. The possibly fertile exceptions are assumed to be offsprings from two hybrid combinations studied in northern Europe: Carex saxatilis x vesicaria and C. rostrata x rotundata. A plethora of assumed primary hybrids of these parentages are found, with pollen abortion and a varying but more or less intermediate morphology. Besides these obvious hybrids are found plants combining characters from the same parental pairs in a morphologically more uniform way, with well developed anthers and pollen, and forming populations and with large and consistent ranges, often in absence of one or both presumed parents. Neither are they intermediate but rather closer to one parent, suggesting back-crossing between primary hybrids and one parent with restoration of fertility. These are C. stenolepis Less. (combining features of C. saxatilis and C. vesicaria but closer to C. saxatilis) and C. rostrata var. borealis (combining features of C. rostrata and C. rotundata but closer to C. rotundata). Carex stenolepis is not documented to reach the Arctic (see Excluded taxa), whereas C. rostrata var. borealis do and is included provisionally below.