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Zamia melanorrhachis

Forests·The stem is subterranean.

Zamia melanorrhachis is a species of cycad native to Colombia, found in forests at low to moderate altitudes. It is characterized by its subterranean stem and compound leaves with dark, prickly petioles and rachises. This dioecious plant produces distinct male and female cones, with the female cones being larger and wine-red to dark red-brown.

Key Facts

  • Native to multiple departments in Colombia, including Amazonas, Córdoba, Meta, and Santander.
  • Grows in forests at altitudes ranging from sea level to 300 meters.
  • Possesses a subterranean stem, typically 5 to 8 cm in diameter.
  • Features upright compound leaves up to 50 cm long with dark purple to black, prickly petioles and rachises.
  • Is dioecious, meaning individual plants are either male or female.
  • Male cones are small and cream to tan, while female cones are larger and wine-red to dark red-brown.
Zamia melanorrhachis
Scientific Name
Zamia melanorrhachis
Common Names

Corocito

Family
Zamiaceae
Native Range

Colombia

Stem Characteristics

Subterranean, 5 To 8 Centimetres In Diameter

Leaf Characteristics
  • Upright oblong compound-leaves
  • Up to 50 centimetres long
  • Dark purple to black petiole up to 25 centimetres long
  • Stalk covered with very small prickles
  • Four to ten pairs of leaflets per leaf
  • Leaflets are lanceolate, pointed on the ends, and toothed on the edges of the outer two-thirds
  • Leaflets are 12 to 15 centimetres long and 1 to 2 centimetres wide in the middle of the leaf
Cone Characteristics
  • Male cones: Ovoid, 1 to 3 centimetres long and 0.5 to 1 centimetre in diameter, cream to tan in color, on peduncles 30 to 50 centimetres long.
  • Female cones: Cylindrical to ovoid-cylindrical, 5 to 8 centimetres long and 3 to 4 centimetres in diameter, wine-red to dark red-brown in color.
Leaf Arrangement
spiral
Seed Characteristics

1 To 1.5 Centimetres Long, 0.5 To 0.8 Centimetres In Diameter

Etymology
The specific name 'melanorrhachis' refers to the dark color of the leaf axis (rachis).

About Zamia melanorrhachis

Zamia melanorrhachis is a species of cycad belonging to the Zamiaceae family, indigenous to Colombia. It is recognized for its distinctive botanical features, particularly its dark, prickly leaf structures and its subterranean stem. The species is found growing within forests at altitudes ranging from sea level up to 300 meters.

Description and Characteristics

The most notable aspect of Zamia melanorrhachis is its subterranean stem, which typically measures between 5 to 8 centimeters in diameter. Each plant produces between two to five upright, compound leaves that can reach up to 50 centimeters in length. These leaves emerge from a dark purple to black petiole, or stalk, which can be up to 25 centimeters long and is covered in very small prickles. These prickles extend into the lower portion of the dark brown to dark purple rachis, which is the central axis of the leaf.

The leaflets themselves are lanceolate in shape, tapering to a point and possessing toothed edges along the outer two-thirds of each leaflet. They measure between 12 to 15 centimeters long and 1 to 2 centimeters wide in the central part of the leaf. Like all members of the Zamia genus, Z. melanorrhachis is dioecious, meaning individual plants are exclusively male or female.

Reproductive structures, known as strobili or cones, differ significantly between sexes. Male cones are ovoid, relatively small (1-3 cm long), and cream to tan in color, borne on long peduncles. Female cones are larger, cylindrical to ovoid-cylindrical (5-8 cm long), and exhibit a striking wine-red to dark red-brown coloration. The seeds produced by the female cones are also distinct, measuring 1 to 1.5 centimeters long and 0.5 to 0.8 centimeters in diameter.

Distribution and Ecology

Zamia melanorrhachis has been documented in several departments of Colombia, including Amazonas, Córdoba, Meta, and Santander. Its natural habitat is confined to forests, typically found at lower to moderate elevations. The species is part of the Manicata clade, a group of closely related species found in northern Colombia.

Etymology

The scientific name, Zamia melanorrhachis, derives from Greek roots. The term 'melanorrhachis' specifically refers to the dark coloration of the plant's rachis, a prominent characteristic of its leaf structure.

Source: Wikipedia ↗

Frequently Asked Questions

What is Zamia melanorrhachis commonly known as?

Zamia melanorrhachis is commonly known as corocito. This common name may be used in local contexts to refer to the plant.

Where can Zamia melanorrhachis be found naturally?

This species is indigenous to Colombia, specifically identified in the Amazonas, Córdoba, Meta, and Santander departments. Its natural habitat is within forests.

What are the distinguishing features of Zamia melanorrhachis leaves?

The leaves are oblong and compound, reaching up to 50 centimeters in length. They grow on dark purple to black petioles, which are covered with small prickles that extend onto the dark brown to dark purple rachis.

How do the male and female cones of Zamia melanorrhachis differ?

Male cones are typically ovoid, smaller (1-3 cm long), and cream to tan in color. Female cones are larger (5-8 cm long), cylindrical to ovoid-cylindrical, and wine-red to dark red-brown.

What does the scientific name Zamia melanorrhachis signify?

The specific epithet 'melanorrhachis' is derived from Greek, referring to the dark color of the leaf axis, or rachis. This highlights a key visual characteristic of the plant's foliage.