Diphasiastrum × issleri

Diphasiastrum × issleri
Scientific classification
Kingdom:	Plantae
Division:	Lycopodiophyta
Class:	Lycopodiopsida
Order:	Lycopodiales
Family:	Lycopodiaceae
Genus:	Diphasiastrum
Species:	D. × issleri
Binomial name
Diphasiastrum × issleri (Rouy) Holub
Synonyms[1]
Diphasiastrum complanatum subsp. complanatum (Rouy) Jermy Diphasium hastulatum Sipliv. Diphasium issleri (Rouy) Holub Lycopodium alpinum race issleri Rouy Lycopodium alpinum subsp. issleri (Rouy) Chass. Lycopodium complanatum subsp. issleri (Rouy) Domin Lycopodium issleri (Rouy) Domin

Diphasiastrum × issleri, known as Issler's clubmoss, is a hybrid species of clubmoss known from northern Europe and a few historical collections in northern Maine.

Taxonomy

D. × issleri is a hybrid between D. alpinum and D. complanatum. Originally placed in a broadly circumscribed Lycopodium as a race of L. alpinum, it was transferred to the segregate genus Diphasiastrum and raised to species level by Holub in 1975.^[2] In the past, it has been treated as a subspecies of D. complanatum. American material was once believed to be a hybrid between D. alpinum and D. tristachyum, but the offspring of those parents is properly known as D. × oellgaardii, which has not yet been found in North America.^[3]

References

1. Tropicos
2. Holub, Josef Ludwig (1975). "Diphasiastrum, a new genus in Lycopodiaceae". Preslia 14: 97–100.
3. Haines, Arthur (2003). The Families Huperziaceae and Lycopodiaceae of New England. Southwest Harbor, Maine: V. F. Thomas Co. pp. 52–53.