Alnus formosana, the Formosan alder, is a species of alder endemic to Taiwan.
Description
The formosan alder is a trees up to 20 meters in height with dark gray-brown bark. The petiole is 1.2-2.2 cm, slender; leaves elliptic or oblong-lanceolate, rarely ovate-oblong, 6-12 × 2–5 cm, hairy in the axils of lateral veins beneath, almost hairless above, rounded or broadly cuneate base, irregularly minutely serrated margin, acuminate or acute apex; lateral veins 6 or 7 on each side of the midrib. It has one female inflorescence, or 2-4 in a cluster, ellipsoid, 1-2.5 cm; peduncle 3–5 mm.
Distribution and habitat
It is found in Taiwan. It is a common species growing on riverbanks from near sea level to .
It is commonly found in disturbed habitats as a
pioneer species.
Ecology
Alnus formosana flowers between May–June, fruiting between July–September.
Uses
This tree is used for soil improvement.
It also finds use in gardens and as a windbreak. The tree trunks is also used in paper pulping and cultivating
snow fungus and
shiitake.
The Atayal people uses A. formosana as a cover crop after clearing a new field, the traditional wisdom being that the soil becomes rich when it is cut cleared again in 10 to 15 years.
Early Han settlers of Taiwan name some places after the occurrence of the plant, the belief being that its occurrence is linked to ground collapse.
