Acacia Mill.

Acacia gummifera is chiefly currently known to the Mediterranean acacia-argania dry woodlands and succulent thickets of Morocco, in association with plants such as Periploca laevigata, Senecio anthephorbium, Launaea arborescens and Warionia saharae.  However there is evidence that this tree occurred in Biblical times as far east as the Holy Land.

Perennial, Shrubs, Stems woody below, or from woody crown or caudex, Taproot present, Nodules present, Stems erect or ascending, Stems less than 1 m tall, Stems 1-2 m tall, Stems solid, Stems or young twigs glabrous or sparsely glabr ate, Leaves alternate, Leaves petiolate, Stipules inconspicuous, absent, or caducous, Stipules setiform, subulate or acicular, Stipules deciduous, Stipules free, Leaves compound, Leaves even pinnate, Leaf or leaflet margins entire, Leaflets opposite, Stipels present at base of leaflets, Leaflets 10-many, Leaves glabrous or nearly so, Inflorescences racemes, Inflorescence axillary, Bracts conspicuously present, Bracteoles present, Flowers zygomorphic, Calyx 5-lobed, Calyx glabrous, Petals separate, Corolla papilionaceous, Petals clawed, Petals orange or yellow, Petals bicolored or with red, purple or yellow streaks or spots, Banner petal suborbicular, broadly rounded, Wing petals narrow, oblanceolate to oblong, Wing petals auriculate, Wing tips obtuse or rounded, Keel petals auriculate, spurred, or gibbous, Keel abruptly curved, or spirally coiled, Keel tips obtuse or rounded, not beaked, Stamens 9-10, Stamens diadelphous, 9 united, 1 free, Filaments glabrous, Style terete, Fruit a legume, Fruit stipitate, Fruit unilocular, Fruit tardily or weakly dehiscent, Fruit indehiscent, Fruit elongate, straight, Fruit oblong or ellipsoidal, Fruits quadrangulate, Fruit or valves persistent on stem, Fruit coriaceous or becoming woody, Fruit exserted from calyx, Fruit compressed between seeds, Fruit beaked, Fruit glabrous or glabrate, Fruit 3-10 seeded, Seeds ovoid to rounded in outline, Seed surface smooth, Seeds olive, brown, or black.

The flowers are cross-pollinated primarily by bumblebees, although the Ruby-Throated Hummingbird, honeybees, butterflies, and moths also visit the flowers. The floral award of these visitors is nectar. According to Robertson (1929), butterflies and moths are not effective at cross-pollination, unlike the bees and hummingbird. The foliage of Black Locust is a food source for  caterpillars of the skippers Erynnis funeralis (Funereal Duskywing), Erynnis icelus (Dreamy Duskywing), Erynnis zarucco (Zarucco Duskywing), and Epargyreus clarus (Silver-Spotted Skipper). The caterpillars of several moths also feed on the foliage; they include such species as Dasylophia anguina (Black-Spotted Prominent), Euparthenos nubilis (Locust Underwing), Mellilla xanthometata (Orange Wing), Pero honestaria (Honest Pero), Sciota subcaesiella (Locust Leafroller), and Zale undularis (Black Zale). See the Moth Table for a more complete list of these species. Other insects that feed on this tree include the treehoppers Cyrtolobus fuscipennis, Hadrophallus constans, Stictocephala brevitylus dolichotylus, Telamona decorata, Thelia bimaculata, and Vanduzea arquata; the aphid Aphis cytisorum; the plant bugs Lopidea robiniae (Black Locust Plant Bug) and Orthotylus robiniae; larvae of the wood-boring beetles Agrilus egenus and Megacyllene robiniae (Locust Borer); larvae of the seed beetle Amblycerus robiniae (Locust Seed Borer) and the leaf beetle Odontota dorsalis (Locust Leafminer); larvae of Dasineura pseudoacaciae (Black Locust Gall Fly); and many others. See the Insect Table for a more complete list of these species. Notwithstanding their toxicity, the seeds are a minor food source of the Thirteen-Lined Ground Squirrel and some upland gamebirds, including the Bobwhite and Ring-Necked Pheasant. While White-Tailed Deer occasionally browse on the foliage of Black Locust without apparent ill effects, it is toxic to such domesticated animals as horses, cattle, and sheep. Because Black Locust is vulnerable to heart-rot fungi, older trees often develop cavities that become dens for bats, screech owls, and woodpeckers. Clonal colonies of Black Locust can provide significant cover for the White-Tailed Deer, Coyote, Red Fox, Striped Skunk, Ring-Necked Pheasant, Bobwhite, and other wildlife in semi-open areas.

Population

Population Trend