Apple Scab Disease: Symptoms, Microscopy, and Life Cycle Diagram #246664 (License: Personal Use)

Panel (a) shows a cross-section of an infected apple with dark, irregular stromata and embedded ascocarps; panel (b) illustrates characteristic olive-brown, velvety leaf spots aligned along veins; panel (c) reveals the microscopic structure of conidiophores erupting through the leaf cuticle, producing chains of conidia. This tripartite diagram is typical of late 1800s mycological texts documenting Venturia inaequalis.

Used in academic and extension resources on plant pathology, particularly for teaching identification of apple scab. Matches user intent for educational, diagnostic, or historical botanical illustration reference.