Pinus maximartinezii Rzed.

Species Identification and Size

Pinus maximartinezii Rzed. is a small tree that grows 5–15 m (16–49 ft) tall, with a trunk diameter reaching up to 50 cm (20 in).

Bark Characteristics

Its bark is brown, thick, and fissured at the base of the trunk.

Needle Structure

Its leaves, called needles, grow in bundles (fascicles) of five; they are slender, 7–13 cm (2+3⁄4–5 in) long, and colored deep green to blue-green.

Needle Stomata

Stomata are restricted to a bright white band on the inner surfaces of the needles.

Closed Cone Dimensions

The cones are ovoid and very large, measuring 15–27 cm (6–10+3⁄4 in) long and 8–14 cm (3+1⁄4–5+1⁄2 in) broad when closed, and can weigh up to 2 kg (4.4 lb).

Cone Development and Color

When young, the cones are green, and they ripen to yellow-brown after 26–28 months.

Cone Scale Structure

The cones have very thick, woody scales, with typically 30 to 60 fertile scales per cone.

Subgenus Scale Distinction

This scale structure is unusual for pines in the soft pine group (Pinus subgenus Strobus), where most species have flexible scales.

Mature Open Cone Size

When mature, the cones open to 10–15 cm (4–6 in) broad.

Seed Characteristics

The seeds are 2–3 cm (3⁄4–1+1⁄4 in) long, with a thick shell and a vestigial 1–2 mm (0.04–0.08 in) wing.

Seedling Cotyledons

Seedlings of this species have 18–24 cotyledons, the highest number recorded for any plant.

Pinyon Pine Distinction

This species differs from all other pinyon pines by its very massive cones and large seeds.

Edible Seed Use

Like other pinyons, its seeds are edible.

Threat to Regeneration

Harvesting of most of the seeds the species produces to use for food threatens the species' survival, as it limits natural pine regeneration.

Native Range

The species has a highly localized range, restricted to only two small areas in the southern Sierra Madre Occidental: Sierra de Morones in southern Zacatecas, and La Muralla in Durango.

Habitat Conditions

It grows at moderate altitudes from 1800 to 2400 m, at 21° North latitude, in warm, temperate, dry climate conditions.

Conservation Status

The Mexican government has classified this species as endangered.

Cultivation Use

It has only recently entered cultivation, where it is grown as a very attractive ornamental tree.