Shrub/Tree Indiana Native Frangula caroliniana [Carolina Buckthorn] Handsome shrub or small tree with dark green, 8 to 10 vein-paired leaves. Fruits are 1/3" diameter, globose and has a sweet taste to it. Changes from red to black as it matures. Fruit ripes (Red) in August and remain on the plant until October or later, by which time it turns black.