Panarctic Flora


340903 Hierochloë odorata (L.) Wahlenb.


Geography: Circumboreal-polar.

Notes: Weimarck (1971) assigned Hierochloë arctica J. Presl as subspecies to H. hirta (Schrank) Borbás, on evidence from morphology and ploidy, perhaps mainly because both are high polyploid and agamospermous. This treatment has subsequently been followed in northwestern Europe (e.g., Weimarck 1980; Elven 1994; Hämet-Ahti et al. 1998; Mossberg and Stenberg 2003; Elven et al. 2005). Tzvelev (1976, PAF proposal) instead assigned subsp. arctica to H. odorata for morphological reasons, as a high-ploid apomictic derivative, and we follow that proposal. Tzvelev included also H. hirta s. str. in H. odorata but H. hirta is morphologically much more different from H. odorata than is subsp. arctica. Transitions between H. hirta s. str. and H. odorata or subsp. arctica have not been observed in northern Europe, whereas subsp. arctica may be difficult to keep apart from H. odorata s. str. In our opinion, H. hirta s. str. deserves rank as species but it does not reach the Arctic. Allred and Barkworth (2007) accepted two species under the names Anthoxanthum nitens (= H. odorata) and A. hirtum.

Only chromosome counts reported after the consistent separation of H. hirta from H. odorata, or from areas where only one of them is known to be present, are considered below.

Higher Taxa