Abstract Plant morphogenesis has long remained a fundamental theoretical puzzle: why does the phyllotactic divergence angle consistently converge to 137.5°, and why do inflorescence and fruit grain arrangements exhibit stable numerical patterns related to the number 14? Based on the 14-Order Unified Field Theory (14FT), this study reveals the essential order-state nature of plant growth: the morphological structures of plant phyllotaxis, inflorescence, and fruit are dimensional projections of the three-dimensional close-packing of regular tetradecahedron units onto a two-dimensional cylindrical surface. The classic 137.5° phyllotaxis golden angle is precisely derived as the optimal unfolding angle of tetradecahedron projection, formulated as \(137.5^\circ = 360^\circ \times (1 - 7/19 \times 1/\phi)\). The 7–8 leaf radiation symmetry of palmate compound leaves originates from 14-order symmetry projection, in which 7 represents the stable orbital number of topological projection, and 8 is an extended coupling configuration containing the central petiole polarity. The 14-row grain arrangement of corn ears and the 14-seed distribution of legume pods are direct topological manifestations of 14-order symmetry in plant reproductive organs. This research provides a first-principles geometric interpretation for botanical morphology and further extends the cross-scale verification system of 14FT (V8) to mesoscopic plant morphology. All theoretical inferences in this paper remain to be verified by systematic morphological measurement and molecular developmental experiments.