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Cycads / ˈ s aɪ k æ d z / are seed plants that typically have a stout and woody trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious , that is, individual plants of a species are either male or female.
Encephalartos lehmannii is a low-growing palm-like cycad in the family Zamiaceae.It is commonly known as the Karoo cycad and is endemic to South Africa. [3] The species name lehmannii commemorates Prof J.G.C. Lehmann, a German botanist who studied the cycads and published a book on them in 1834. [3]
This cycad is tree-like, with a stem up to 2.5 m tall and 30–45 cm wide. Its leaves are bluish or silvery, 100–150 cm long, and have a strong keel. The leaflets are lanceolate, 15–20 cm long, and arranged oppositely along the rachis at a 45–80° angle. They have smooth margins, although the lower leaflets may have a single spine.
Since Z. integrifolia is a cycad, which are the only group of gymnosperms that form nitrogen-fixing associations, it depends on microbes as a source of nitrogen. It forms a symbiotic relationship with nitrogen-fixing cyanobacteria , which live in specialized roots called coralloid roots and are green in color despite not actively ...
The pollen of this cycad is not airborne. Typically, the pollen is transported by a host-specific insect from male to female cones when they are receptive. [6] Pollen of L. peroffskyana is carried by Tranes group weevils. The weevil's life-cycle occurs in the male cones, but many individuals visit female cones during their lives, covered in pollen.
The Natal cycad grows to a height of 6 m (20 ft) or more. It may have a single trunk or may be branched from the base. The trunk is topped by a rosette of large, evergreen, pinnate leaves somewhat twisted near the tip, which may be 3 m (10 ft) long. The leaflets are dark green and about 6 cm (2.4 in) wide; they may be untoothed, or they may ...
Encephalartos ghellinckii Lem. or Drakensberg cycad is endemic to South Africa, and is one of about 70 species found in sub-Saharan Africa. Strongly associated with the Natal Drakensberg , this 3m tall evergreen species is found from the foothills to fairly high altitudes, growing on stream banks, steep grassy slopes and sandstone outcrops .
It is the largest of all cycads, with multiple stems both upright and prostrate, each as much as sixty feet (18 meters) in length, [3] and bearing a rosette of massive once-pinnate fronds up to 25 feet (eight meters) in length, forty inches (100 cm) in width, and with a petiole or stalk up to three inches (7.6 cm) thick where it joins the stem or trunk.