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Saturday, July 20, 2013

Betula papyrifera - Paperbark Birch

The paperbark birch (also known as the canoe birch) is a medium to large (50-70') deciduous tree native to the Pacific Northwest and all across Canada to the east coast.  Pyramidal when young developing into a more rounded habit. You can see from the picture the trees do not weep like the European Weeping Birch. Often planted as a multi-stemmed specimen. "Clump Birch" is a name for any birch species sold with 3 main stems. 



Trunks stay white pretty long.





The deciduous leaves are ovate, 2-4" with a narrow tip. Margins usually doubly-serrated. Look for the presence of tufts of hairs in the axils of the veins on the lower surface to help distinguish between this and European White birch. Look for 4-5 vein pairs to help distinguish this from B. jacquemontii.



Lower surface showing the hairs.




One of the 3 trees mentioned below has very nicely doubly serrated margins, almost looking cut leaf like. Might be a nice one to graft. You can see the one on the left has nicer margins.



Twigs are red-brown and slightly glandular. Buds are usually brown and green striped.




If you look at an older stem, still young but older, you will see what looks like 2 leaves coming off of each node. They are really coming from the bud and develop like small spurs.



One of the best of the many white barked birches. Heavily lenticeled as well. Peeling bark reveals a yellowish pink new layer of bark. All branch ridges and scars develop black areas making for a great contrast.




Male flowers in a 2-3" long catkin overwintering. Female emerging in spring, red color and erect on branches.


Fruit is a small winged nut, developing from a catkin. This is the female ready to start releasing seeds. 




Here are the fruit and some bracts.




Fall color is the best. Really, of all the birch trees I have seen this one puts on the best yellow color.



All birch trees need ample water. They used to thrive in our heavily irrigated lawns but we don't do lawns anymore, do we? Anyway, the thrive best in cool climates, but you will see them everywhere.


Misidentification:
Betula jacquemontii around here. Look at the buds. Differs in habit from the European Weeping birch as the lateral branches are only lightly pendulous.

Location:
Aptos
McGregor Dr. at Perch Way. They are planted on one side of the driveway with Betula pendula on the other. Intentional? Maybe, but a great spot to look at them side by side.

Santa Cruz
Front St all along the side of the street with SC Book Shop.