What kind of fruit is this?

Plum is also known as ebony, black brown, scientific name is black plum, and English name is plum. Because this variety was introduced from the United States, the fruit color is purple-black, also called American black plum and American plum. Drupe is spherical, ovoid or nearly conical, with a diameter of 3.5-5 cm. Cultivars can reach 7 cm, yellow or red, sometimes green or purple. The stem is concave, slightly pointed at the top, with longitudinal grooves at the base and covered with wax powder. The nucleus is oval or rectangular with wrinkles. It blooms in April and bears fruit in July-August. He is a new high-grade fruit variety bred by American researchers from the hybrid offspring of China plum and European plum after decades of efforts. It has changed the shortcomings of China Yi Lee, such as cracking fruit, heavy astringency, indigestion and monotonous color, and is deeply loved by consumers because of its unique shape, bright color, sweet flavor and storage resistance. American black plum has strong adaptability, good disease resistance and certain salt-alkali resistance, which is suitable for cultivation in neutral or acidic soil. The tree is short, suitable for close planting, easy to prune, extensive in management, early in fruiting, high in yield, saving fertilizer and labor, and high in economic benefits.