The Flora of Svalbard

Vegetative reproduction by shoot fragments that become detached. Pollen of poor quality and no ripe fruits have been observed. Dispersal is probably by shoots that attach to animals e.g. geese or reindeer.

The species of the genus Coptidium differ from those of the genus Ranunculus in several features, the most evident being the thick, white, creeping underground stems and the leaves and flowers arising mostly singly above ground from these stems. There is nothing similar in Ranunculus. Another difference is the fragrant flowers of Coptidium (no fragrance in Ranunculus). Less visible is the corky floating tissue in the fruits of Coptidium, absent in Ranunculus. Coptidium pallasii and C. spitesbergense are both aquatic and have similar growth form. Flowering plants are easily distinguished by white vs. pale yellow flowers and by flower size (much larger in C. pallasii). Sterile plants are distinguished by the blade: entire or dissected for 20−50(−70)%, with one broad mid lobe and 1−2  smaller lateral lobes reaching about 2/3 the length of the mid lobe in C. pallasii vs. dissected for (50−)60−80%, and lateral lobes are often dissected again, in C. spitsbergense.

Helophyte or hydrophyte. Growing in wet, slightly acidic to slightly calcareous moss tundra, often in or in the margin of shallow ponds.

Coptidium spitsbergense is probably a seed-sterile triploid hybrid between C. pallasii and C. lapponicum (Elven et al. 2011). In Svalbard, it occurs in large stands and nearly always in the absence of one (C. pallasii) or both assumed parents. It is rather common compared to C. pallasii, which is only found at 8 locations, and also more frequent than its other assumed parent, C. lapponicum. Due to its frequency, it is obviously not a case of occasional hybridization. Its range is assumed to be mainly or entirely due to animal dispersal of shoot fragments. 

Both the total range and the name of this plant has been discussed. Tolmachev (1971) made the identification with Ruprecht's var. minimus, thereby accepting the species also outside Svalbard. Furthermore, it is now confirmed from the island Kolguev and several other Russian regions and from NC and NE Canada (Cody et al. 1988). A survey of material (ALA, CAN) in 2009 revealed no specimens from Alaska or the Yukon Territory. 

Two name forms have been applied: "spitsbergensis" ("spitzbergensis") and "spetsbergensis". When Hadač in 1942 published his name Ranunculus spitsbergensis,  he did it with a separate type and did not base it on Nathorst's name from 1883, var. spetsbergensis. Jalas (1988) showed that Nathorst's name, spelling and type have priority at varietal level, whereas Hadač' name, spelling and type have priority at species level.

Cody, W.J., Blondeau, M. & Cayouette, J. 1988. Ranunculus xspitsbergensis (Nath.) Hadac, an addition to the flora of North America. – Rhodora 90: 27–36.

Elven, R., Murray, D.F., Razzhivin, V. & Yurtsev, B.A. 2011. Annotated Checklist of the Panarctic Flora (PAF). – Oslo: CAFF/University of Oslo.

Jalas, J. 1988. Atlas florae europaeae notes, 9–11. – Annales Botanici Fennici 25: 295–299.

Tolmachev, A.I. 1971. Ranunculaceae p.p. – Pp. 123–231 in Tolmachev, A.I. (ed.), Flora Arctica URSS. VI. Caryophyllaceae–Ranunculaceae. – Nauka, Leningrad.