Leaves: usually over 3 cm long, widest above the base with a pointed tip. Fruit: borne in catkins at least 1 cm thick, scales have ascending lobes. Bark: grayish brown, not peeling. Twigs: have a wintergreen scent when scratched. Characteristics: intermediate of the parents.
Similar species: Betula x purpusii and Betula x sandbergii are both hybrids that share a common parent, Betula pumila. Betula pumila is a shrub, and both of these hybrids are more shrub-like than their other parents. Betula x sandbergii is distinguished from B. x purpusii by its lack of wintergreen odor on the stems, cross-shaped lobes on the scales of female catkins, and fewer veins on the leaves.
Flowering: May to June
Habitat and ecology: Rare in the Chicago Region, but may be found in boggy woods.
Occurence in the Chicago region: native
Etymology: Betula is the Latin name for birch. Purpusii is named after early 20th century German plant collectors, Carl and Joseph Purpus.
Author: The Morton Arboretum
From Flora of Indiana (1940) by Charles C. Deam
This is a natural hybrid [Betula lutea x B. pumila var. glandulifera). I found it in a tamarack bog about a fourth of a mile north of Mineral Springs Stop on the South Shore Electric Line, in Porter County and in a marsh about two and a half miles northwest of Porter in the same county.