The species are superficially similar to Geum (with which they share the common name avens), Potentilla, and
Fragaria (strawberry). However, Dryas are distinct in having
flowers with eight petals (rarely seven or up to ten), instead of the five petals found in most other genera in the Rosaceae. The flowers are erect and white with a yellow centre (Dryas integrifolia, Dryas octopetala) or pendulous and all-yellow (Dryas drummondii), and held conspicuously above the small plants. This makes them very popular in
rockeries and
alpine gardens. The hybrid Dryas × suendermannii, with cream coloured flowers, has gained the
Royal Horticultural Society's
Award of Garden Merit.[5][6]
Dryas tolerates a wide variety of unshaded habitats, including alpine situations with sand or gravel substrate, similar substrates in flat
tundra lowlands, and also
fen habitats upon organic substrate where some shading from adjacent
sedges or shrubs may occur.
The
Younger Dryas and
Older Dryasstadials are geological periods of cold temperature that are named after Dryas octopetala, which flourished during that time and is used as a
fossil indicator of those periods.[citation needed][7]
^Swensen SM, Mullin BC (1997). "The impact of molecular systematics on hypotheses for the evolution of root nodule symbioses and implications for expanding symbioses to new host plant genera". Plant and Soil. 194 (1/2): 185–192.
doi:
10.1023/A:1004240004063.
JSTOR42948119.
S2CID35125701..
^Kohls SJ, Baker DD, van Kessel C, Dawson JO (2004). "An assessment of soil enrichment by actinorhizal N2 fixation using δ15N values in a chronosequence of deglaciation at Glacier Bay, Alaska". Plant and Soil. 254 (1): 11–17.
doi:
10.1023/A:1024950913234.
S2CID25039091.
^
abKohls SJ, van Kessel C, Baker DD, Grigal DF, Lawrence DB (1994). "Assessment of N2 fixation and N cycling by Dryas along a chronosequence within the forelands of the Athabasca Glacier, Canada". Soil Biology and Biochemistry. 26 (5): 623–632.
doi:
10.1016/0038-0717(94)90251-8.
^Deslippe JR, Egger KN (2006). "Molecular diversity of nifH genes from bacteria associated with high arctic dwarf shrubs". Microbial Ecology. 51 (4): 516–25.
doi:
10.1007/s00248-006-9070-8.
PMID16649061.
S2CID11453460.
^(Reported as Dryas drummondii var. eglandulosa.) Kohls SJ, Thimmapuram J, Buschena CA, Paschke MW, Dawson JO (1994). "Nodulation patterns of actinorhizal plants in the family Rosaceae". Plant and Soil. 162 (2): 229–239.
doi:
10.1007/BF01347710.
JSTOR42939545.
S2CID36071796.