Another example of metamorphoses, this time for a seedling from a 2500 m height. Since the last fall, it grew up from a seed, through a very hairy seedling, to an almost 1 m tall tree. Only during last two months, the top part of its stem become reminding one of Betulaceae, with whitish spots on the bark. The leaves, however, are pretty large, up to 10 cm long, as you can see it against the 8" block of the wall. Only 5 species are listed for Utah: Alnus incana, Ostrya knowltonii, Betula glandulosa, Betula nana, and Betula occidentalis. All three birches should have leaves smaller than 5 cm, by the key. Could it be Alnus or Ostrya? The key requires knowledge about their inflorescences, which are many years to wait for.
Looks like a paper birch. Jumbo leaves are seen on seedlings and vigorous growths on older specimens. Maybe there is something in this. "Betula × utahensis Britton (= B . occidentalis Hooker × B . papyrifera Marshall) is a common hybrid marked by intermediate characteristics" http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233500259
Thank you, Ron! I agree, it quite might be young-age-related. Among my collection, I only could find two species. The first is probably Alnus incana. It definitely looks different. The next three, which I preliminary assigned to Betula occidentalis are from three different spots at 3-5 km around the place of origin of my seedling. None of them has such white spots on the leaves (also may be age-related?). Need to wander around to see what else I can find nearby. At least I know what to look at now.
