Mimosa or Silk-tree or Albizia
Albizia julibrissin
Fabaceae - Legume

Description

Leaves: Alternate; twice pinnately compound; 10 to 25 pinnae (the smallest branches of the leaf that hold the leaflets), each with 40 to 60 small, leaflets; deciduous; leaflets sickle-shaped and oblong, uneven at the base, 1/4" to 1/2" long, margins entire, slightly hairy on midribs beneath; dark green with no notable fall color; leaves emerge in May or June.

Twigs/buds: Twigs glabrous; angled; green; with many small lenticels. No terminal bud; lateral buds small, round, brown.

Flowers/fruit: Flowers perfect, pink, with many pink stamens 1" long or more; flowers arranged in small heads at ends of branches, emerging continuously from May to August. Fruit a thin, flat, strap- shaped legume; gray-brown; 4" to 6" long and 1" wide; matures in September and October and persists through the winter, often in large numbers.

Bark: Smooth and gray-brown.

Wood: Little known and unimportant; ring-porous.

General: Native from China to Iran, but heavily planted and naturalized in the southeastern U.S. Small to medium sized with a broad, flat-topped canopy. Fairly susceptible to pests in the southeastern U.S., but less problems here in Utah. Tolerant of heat, dryness, high soil pH and salinity. Shade intolerant. May be insect and/or disease prone, especially when stressed. Fruit and/or plant part can be nuisances; use fruitless varieties if possible.

Landscape Use: This tree is popular because of its fine texture and showy pink flowers present through much of the summer, though litter can be a problem. It is damaged by temperatures below about -5 degrees F and shouldn't be planted in colder locations, but may do well on warmer sites along the Wasatch Front, as well as in the St. George area. I have seen a mimosa planted in Logan that looks like it grows well but dies to the ground most years. Doing well on the UofU campus. Zones 6-9.

Cultivars: 'Charlotte', 'Durazz', 'E.H Wilson', 'Flame', 'Ishii Weeping', 'Merlot Majik', 'Summer Chocolate', 'Tryon', 'Union'.

Characteristics

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