Dioon edule

Dioon edule

Dioon edule is a representative of cycads ( Cycadales ) and belongs to the genus Dioon.

Features

The tribes are tree shaped and erect or decumbent. The stem is 3 feet high or higher at a diameter of 20 to 40 cm. The trunk is covered with the remaining leaf bases and the Cataphyllen.

The many leaves are stiff, erect, green to slightly bluish green. They are 0.9 to 1.4 m long 17.5 and 20 cm wide and flat or slightly keeled. Young leaves are hairy green or yellow-brown, slightly white, but soon glabrous. The petiole is 3-13 cm long and unarmed. The leaflets are available in 80 to 130 pairs. They are linear - lanceolate, gradually narrowed to the tip, standing separately, only to blade tip and overlapping. Mostly, they are at right angles from the rachis. You will go shorter, but not reduced to apex and leaf base to spines. The middle leaflets are 6-12 cm long and 5-9 mm wide; the leaf margin is slightly rolled down and bears no spines, except for seedlings and young plants.

The female cones are individually, initially upright, inclined slightly later. They are ovate, 25-29 cm long and 19-24 cm in diameter; they are densely hairy except the lowest one to two Sporophyllreihen. The stem is 4-5 cm long and hidden by the Cataphylle, so that the pin appears frequently sitting. The sporophylls are 65 to 72 mm long. The lying on the journal surface side of the sporophyll is long triangular 9.8 to 11 cm high, 4.5 to 5.5 cm wide and densely pubescent. The sarcotesta of the seed is the ripe yellow. The Sklerotesta are oval to spherical, 24-30 mm long, 19-22 mm in diameter and more or less smooth, but with 12 to 16 indistinct longitudinal furrows.

The male cones are individually. They are cylindrical, 17.5 and 20 cm long with a diameter of 6 to 7.5 cm and densely hairy white or gray -brown. The shaft is 3 to 3.5 cm long; the journal appears often sitting. The sporophylls have a pointed or oval top. The lying on the journal surface side of the sporophyll is triangular, 12 to 15 mm wide and 10 mm high, densely hairy. The sporangia are in a group that also extends to the sides of the sporophyll.

Dissemination and locations

The species is endemic to Mexico. It occurs in the states of Hidalgo, Querétaro, San Luis Potosí, to the south of Tamaulipas and Veracruz. The site is located on the eastern slopes of the Sierra Madre Oriental. It grows mostly in the transition region from the tropical deciduous forest to oak forest, on rocky sites or on rocky slopes in 500 to 1500 m above sea level. The mostly in summer precipitation falling per annum from 1000 to 1500 mm. The species is not considered to be at risk. The collection of entire plants or the cutting off of heads with the leaves as ornamental jewelry has in some areas, greatly reduced the stocks.

System

As the area of the species is strongly disjoint, there are several morphologically easily distinguishable forms. Whitelock (2002 ) believes that these partially separate species could be. The distinction between two varieties is widely in use, the nominate form is divided by Whitelock even further:

• Var edule, as described above. From north to south there are the following forms: Valles - form
• Río Verde - form
• Querétaro - form
• Jacala form
• Palma Sola - form

Use

The Style epithet edule means edible and refers to the use of the seeds, which are called in Mexico palma de dolores, Chamal and palmita. Today, they are hardly eaten.

Documents

• Loran M. Whitelock: The Cycads. Timber Press, Portland, OR 2002, ISBN 0-88192-522-5, pp. 163 f