Zamia lawsoniana has an underground stem, branching in older plants, up to long and in diameter. There are two to five (rarely up to 14) compound leaves on a stem apex, standing upright. Leaves are long, emerging light-green, darkening to green when mature. The
petiole (leaf stalk) is long, covered with thin
prickles up to long. The
rachis (leaf shaft), long, is also covered with prickles on the third of it length towards the base of the leaf. The petiole and rachis are straight in young specimens, developing a slight twist with age. There are 16 to 32 pairs of
leaflets, with medial leaflets long and wide. The leaflets are
sessile (attached directly to the rachis with no stalk), coriaceus (leathery), linear, with a longitudinal groove, with a symmetrical acute apex. The outer one-third of the leaflet margins are toothed, with up to nine teeth on each side. Like all cycads,
Zamia lawsoniana is
dioecious, with individual plants being either male or female. Male plants have one to three
strobili (reproductive cones) on their apex. The male strobili are erect, long and wide, on a long
Peduncle (stalk). Cone and stalk are light yellow in color and covered with hairs. Female plants have one (rarely, two) strobilus, long and wide, light-brown in color covered with hairs, standing erect on a long brown peduncle, also covered with hairs. The seeds are ovoid, up to long and wide. The
sarcotesta (seed coat) is smooth, light pink when immature, and red when mature.
Zamia lawsoniana is distinguished from neighboring species such as
Z. loddigesii,
Z. spartea, and
Z. stenophyllidia by details of leaf and strobili morphology. ==Distribution and habitat==