Dioon edule var. angustifolium is one of the most distinctive members of the genus Dioon (family Zamiaceae), endemic to the eastern flank of the Sierra Madre Oriental in north-eastern Mexico. It is immediately recognisable by its exceptionally narrow, almost linear leaflets — the very character that gives the variety its epithet (angustifolium, "narrow-leaved") — which lend the rosette a fine, feathery elegance seldom seen among cycads. Confined to the states of Tamaulipas and Nuevo León at elevations of roughly 450–1075 m (1500–3500 ft), it represents one of the northernmost expressions of an ancient, relictual lineage. In its homeland the dioons are traditionally known as palma de la virgen or chamal. The plant develops a stout, columnar trunk that seldom exceeds 1 m in height and measures 175–225 mm in diameter, crowned by a symmetrical rosette of stiff, leathery fronds. The leaves are straight and flat, reaching about 0.8 m in length and 160 mm in width, and display a characteristic dull, glaucous green. The closely set leaflets — 60–110 mm long but only 4–6 mm wide — are entirely spineless along their margins, a diagnostic feature of the Dioon edule complex (marginal spines appear only on seedling and juvenile foliage and are soon lost with maturity). The densely tomentose female cones measure about 200 × 150 mm and ripen in only 8–9 months — far faster than the 12–18 months typical of every other Dioon — releasing seeds whose irregularly ovoid to subglobose sclerotesta (19–25 mm) is wrapped in a medium-yellow sarcotesta. The epithet edule recalls the historical use of the starchy seeds, traditionally processed into flour by indigenous peoples only after careful detoxification. Exceptionally narrow leaflets (4–6 mm wide) producing a slender, fine-textured crown Slow-growing and long-lived, building a stout caudex over many decades Endemic to Tamaulipas and Nuevo León, along the Sierra Madre Oriental (450–1075 m) Spineless leaflet margins — a key diagnostic of the Dioon edule complex Glaucous, dull-green leathery fronds borne in a symmetrical rosette Rapid female-cone maturation (8–9 months), a trait unique within the genus This variety is also encountered under the synonym Dioon angustifolium and the horticultural names Narrow-leaved Dioon and Mexican cycad. Across its range it shows notable geographic variation: the populations near Linares (Nuevo León) form its principal stronghold, plants from Victoria are stouter with broader leaves, and those from Soto la Marina — at lower elevations — bear longer leaflets inserted on the rachis at an acute angle, differences attributed to a long period of genetic isolation among disjunct colonies. As a living representative of one of the most archaic seed-plant lineages on Earth, it is a prized acquisition for the discerning collector. IMPORTANT: Plant show adult plant leaves not for sale. The offer is for a plant in the dimension indicated in description.
