Panarctic Flora

342631 Poa aff. laxa

• Poa laxiuscula sensu Soreng et al. (2003), non (Blytt) Lange, Fl. Dan. 17, 50: 4, t. 2946 (1880).

2n= (1) ca. 65 (ca. 9x). - Soreng (2007, secondary report).
(2) 70 (10x). - Soreng (2007, secondary report).

Geography: North American (NE): CAN GRL.

Notes: Soreng and Gillespie: This is an undescribed species known from western Greenland and northeastern Canada. It is possibly hybridogeneous from Poa laxa subsp. fernaldiana and P. glauca but its range is entirely north of the range of P. laxa subsp. fernaldiana (from Newfoundland south to New England). CpDNA data group it with subsp. fernaldiana. Soreng (2007) reported it with chromosome numbers (2n = ca. 65, 70) higher than in P. laxa s. lat. (2n = 28, 42). It is pollen sterile. It is not known whether it reproduces by seeds, but seed reproduction (possibly by agamospermy) is probable from its independent range. Soreng is in the process of describing this species in 2009.

Elven and Soreng: Soreng et al. (2003) tentatively named this species P. laxiuscula (Blytt) Lange with the comment: "This may be the correct name for material previously referred to P. laxa subsp. flexuosa (Sm.) Hyl. in Canada and Greenland. If not it requires a new name". Lange (1887) applied the name P. laxiuscula to a Greenland plant, probably the one in question here, but he based it on a Scandinavian varietal name that clearly belong within P. glauca (syntypes in O inspected): P. aspera Gaudin var. laxiuscula Blytt, Norges Fl. 1: 122 (1861), described from Scandinavia, Fries, Herb. Norm. fasc. 3: 95, lectotype not chosen. The name P. laxiuscula is therefore inapplicable for the Greenland and Canadian plant in question.