Alexis wrote today’s entry:
Species of Bartramia, including the pictured Bartramia pomiformis, are called apple mosses because of the round shape of their sporangia (spore-containing capsules). One of about one hundred species in the genus, Bartramia pomiformis has a circumboreal distribution, extending from arctic latitudes to as far south as North Africa. This species forms loose tufts and turfs on moist rock outcrops and cliff shelves, from subalpine elevations down to sea level (see Schofield’s Some Common Mosses of British Columbia and Vitt et al’s Mosses, Lichens & Ferns of Northwest North America).
Bartramia pomiformis is distinguished in part by its long, slender and flexuous leaves, which are light green to bluish-green in colour. When dry, however, the leaves are twisted and contorted (see Ireland’s Moss Flora of the Maritime Provinces).
Bartramia pomiformis can be confused with Bartramia ithphylla, though the latter is only found in alpine and subalpine areas and its leaves remain straight when dry (from Schofield’s Some Common Mosses of British Columbia 1992). Also similar is Bartramia stricta (PDF), which lacks sheathing (leaves clasping and surrounding the stem base) and whose wet leaves are typically more erect than those of Bartramia pomiformis.