To valmue-arter på Svalbard, og litt om fjell- og polarvalmuer

Abstract

Morphological investigations confirm that there are two species of Papaver in Svalbard: P. dahlianum and P. cornwallisense. The two most distinctive diagnostic characters are the number of stamens and the length of papillae on the stigmatic rays. Papaver cornwallisense has few stamens, usually 16 but sometimes as few as 4 or 8 or as many as 24, and short papillae (0.15–0.4 mm). Papaver dahlianum usually has 25–35 stamens and conspicuously long papillae (0.5–0.9 mm). In addition, P. cornwallisense has smaller flowers than P. dahlianum and these are mostly white. The fruit of P. cornwallisense is subglobular and narrow beneath the stigmatic disc, whereas that of P. dahlianum is urn-shaped and broadest immediately beneath the disc. There are also some smaller differences in leaf lobes, which are more obtuse in P. cornwallisense than in P. dahlia-num,and leaf pubescence, which is sparse and white in P. cornwallisense, denser and more yellowish in P. dahlianum. In Svalbard, P. dahlianum is the most common of the two, occurring throughout the archipelago, but P. cornwallisense is also common, particularly in western Spitsbergen (where most people visit), where it constitutes almost exactly 50 % of the collected plants in the herbaria. The two species often grow intermixed, both in Svalbard as well as in Greenland and Canada (where they are about equally common). No hybrids or transitional forms are known. A molecular investigation supports the presence of two species.