#seed morphology

• Amphispermous — Having seeds surrounded by a double envelope or seminal structures with a bilateral arrangement; a morphological term describing plants or plant organs whose seeds feature a doubled outer protective coat or a symmetrical configuration on both sides of the placental axis. This structural type ensures increased resistance of the embryo in unstable climatic environments.
• Amphitropous — Describing plant ovules or embryos: strongly curved in the shape of a horseshoe, such that the embryo sac and nucellus are structurally bent on both edges, causing the hilum to be placed in a median position adjacent to the funiculus. This unique anatomical adaptation optimizes the vascularization of the developing seed.
• Awn — A filiform, rigid or flexible, often sharp extension that continues the glumes or lemmas of spikelets in most graminaceous plants (such as wheat, barley, or rye). In a broad or anatomical sense, the term describes any linear, sharp, and thin structural formation resembling a coarse hair, serving to protect seeds or to cling to animal fur for dissemination.