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Knowlton Hop Hornbeam, Western Hop Hornbeam, Wooly Hop Hornbeam, Ironwood
Ostrya knowltonii


Knowlton or western hop hornbeam is an uncommon small tree found at high elevations in the northern Trans-Pecos. It is found in canyons of the Guadalupe Mountains.

Plant Habit or Use: small tree

Exposure: sun

Flower Color: reddish-brown

Blooming Period: spring

Fruit Characteristics: cone-like cluster of small nuts enclosed in bladder-like sacks, resembling hops. Caution! Contains stinging hairs.

Height: to 25 ft.

Width: to 15 ft.

Plant Character: deciduous

Heat Tolerance: high

Water Requirements: low

Soil Requirements: alkaline

USDA Hardiness Zone: 6

Additional Comments:

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