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Thornless Common Honeylocust   arrow

Gleditsia triacanthos var. inermis (gle-dit’-se-a try-a-kan’-thus ee-ner’-mis)
Family: Caesalpinaceae, Cassia; Formerly Fabaceae, bean family)


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Description

Honeylocust leafLeaf: Oddly pinnate or bipinnately compound. 20-30 oblong leaflets, each 1-2 inches long, broadest at base, rounded or blunt at base and tip. Hairy on central vein beneath, hairy petiole. Very fine toothed margin. The whole leaf is 6-15 inches long. Base of petiole swollen, enclosing bud. Leaflets usually have no leafstalk. Leaves may be clustered towards branch tip.

Bud: Hairless, usually embedded into the stem, making the bud very hard or impossible to see. Smaller buds may be above larger ones. True terminal bud absent.

Leaf Scar: Hard to see. Roundish with 3 bundle scars. Surrounds buds.

Stem: Stout. Native Honeylocust may be armed with long thorns that are actually modified branches. (Most Honeylocust in the landscape are thornless – “inermis”.) Zig-zaggy branching. Shiny, smooth, reddish-brown brittle. Mottled or streaked. Very knobby. Enlarged leaf nodes.

Bark: Mostly smooth, but round in spots, as if smoothed by a trowel.

Pith: Round, continuous, pale or pinkish.

Flower: Small, greenish-yellow. Fragrant. Blooms in May or June.

Fruit: Brownish-red, flat, slightly curved, 6-16 inch long, leathery pod. Seeds rattle inside.

Habit: Large, open canopy. Horizontal, zig-zagging branches. 50 feet by 40 feet.

Culture: Moderate moisture requirement. Tolerant of mild soil compaction making it the most used sidewalk tree. Full sun. Greatly overused in urban landscapes.

Cultivars:

  • Fairview — 40 feet tall by 40 feet wide. Fruitless.
  • Imperial — 30 to 35 feet tall. Thornless, round crown, some fruit.
  • Moraine — 40-50 feet tall by 45 feet wide. Fruitless. Darker green leaves
  • Shademaster — 70 feet tall by 50 feet wide. Ascending branches, dark green leaves, may have some pods.
  • Skyline — 45 feet tall by 35 feet wide. Compact, ascending branches. Pyramidal. Dark green leaves.
  • Sunburst — 30-35 feet tall. New growth golden, changing to bright green. Needs regular irrigation. Extremely prone to Honeylocust Seed Pod Gall Midge.

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