Encephalartos caffer
Encyclopedia
Eastern Cape dwarf cycad (Encephalartos caffer) is a rare cycad
from the genus Encephalartos
. It typically has an underground stem, with a small portion on top, the stem is only very rarely branched and may be as much as 40 cm long. Emerging from the top are long, pinnate
, dark green leaves up to 1 metres (3.3 ft) long. These often have a distinctive ruffled, feathery appearance, caused by the numerous, clustered leaflet
s being irregularly twisted from the central stalk and pointing out in different directions. New leaves are brown and woolly at first but most of the hair is lost as they mature, although they never become completely smooth or glossy. Both male and female plants bear single reproductive cones made up of a series of spiraled scales, which become greenish-yellow when mature. In the female, two largish, glossy, scarlet-coloured seeds are formed on top of each cone scale.
Found in the coastal belt and up to 100 km inland, usually growing in grassveld but also occurring in adjacent bush, possibly due to shifting boundaries caused by veld fires.
, meaning that there are separate male and female plants, and the female produces seed
s while the male produces pollen
. Plants of this taxon
have generally been considered to be wind pollinated, but several recent studies suggest that insect pollination is more likely. The seeds produced are typically large with a hard, stony layer (sclerotesta) beneath a fleshy outer coat (sarcotesta), attracting animals such as birds, rodents and small mammals, which serve as dispersal agents. In most cases, the fleshy coat is eaten off the seed rather than the entire seed being consumed. Cycads are long-lived and slow-growing, with slow recruitment and population turnover.
All cycads possess 'coralloid' (meaning coral-like) root
s. These roots contain symbiotic
cyanobacteria that fix gaseous nitrogen
from the atmosphere and provide essential nitrogenous compounds to the plant. This can be a great advantage, as many cycads grow in nutrient-poor habitats.
and Albany
districts.
A few viable colonies are protected on state-owned land, and a large colony occurs in the Cape provincial cycad reserve near Grahamstown
, where plants are regularly inspected. Here, many seedlings can be seen amongst the mature plants, and the species therefore seems to be in no immediate danger of extinction.
E. caffer is classified as Near Threatened (NT) on the International Union for Conservation of Nature's Red List
2007, and listed on Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).
Cycad
Cycads are seed plants typically characterized by a stout and woody trunk with a crown of large, hard and stiff, evergreen leaves. They usually have pinnate leaves. The individual plants are either all male or all female . Cycads vary in size from having a trunk that is only a few centimeters...
from the genus Encephalartos
Encephalartos
Encephalartos is a genus of cycad native to Africa. Several species of Encephalartos are commonly referred to as bread palms, bread tree or Kaffir bread since a bread-like starchy food can be prepared from the centre of the stem. All the species of Encephalartos are endangered...
. It typically has an underground stem, with a small portion on top, the stem is only very rarely branched and may be as much as 40 cm long. Emerging from the top are long, pinnate
Pinnate
Pinnate is a term used to describe feather-like or multi-divided features arising from both sides of a common axis in plant or animal structures, and comes from the Latin word pinna meaning "feather", "wing", or "fin". A similar term is pectinate, which refers to a comb-like arrangement of parts...
, dark green leaves up to 1 metres (3.3 ft) long. These often have a distinctive ruffled, feathery appearance, caused by the numerous, clustered leaflet
Leaflet
A leaflet in botany is a part of a compound leaf. A leaflet may resemble an entire leaf, but it is not borne on a stem as a leaf is, but rather on a vein of the whole leaf. Compound leaves are common in many plant families...
s being irregularly twisted from the central stalk and pointing out in different directions. New leaves are brown and woolly at first but most of the hair is lost as they mature, although they never become completely smooth or glossy. Both male and female plants bear single reproductive cones made up of a series of spiraled scales, which become greenish-yellow when mature. In the female, two largish, glossy, scarlet-coloured seeds are formed on top of each cone scale.
Range and habitat
Approximately 10,000 mature individuals are confined to the Eastern Cape Province of South Africa .Found in the coastal belt and up to 100 km inland, usually growing in grassveld but also occurring in adjacent bush, possibly due to shifting boundaries caused by veld fires.
Biology
Cycads are dioeciousDioecious
Dioecy is the property of a group of biological organisms that have males and females, but not members that have organs of both sexes at the same time. I.e., those whose individual members can usually produce only one type of gamete; each individual organism is thus distinctly female or male...
, meaning that there are separate male and female plants, and the female produces seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s while the male produces pollen
Pollen
Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...
. Plants of this taxon
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
have generally been considered to be wind pollinated, but several recent studies suggest that insect pollination is more likely. The seeds produced are typically large with a hard, stony layer (sclerotesta) beneath a fleshy outer coat (sarcotesta), attracting animals such as birds, rodents and small mammals, which serve as dispersal agents. In most cases, the fleshy coat is eaten off the seed rather than the entire seed being consumed. Cycads are long-lived and slow-growing, with slow recruitment and population turnover.
All cycads possess 'coralloid' (meaning coral-like) root
Root
In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. This is not always the case, however, since a root can also be aerial or aerating . Furthermore, a stem normally occurring below ground is not exceptional either...
s. These roots contain symbiotic
Symbiosis
Symbiosis is close and often long-term interaction between different biological species. In 1877 Bennett used the word symbiosis to describe the mutualistic relationship in lichens...
cyanobacteria that fix gaseous nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
from the atmosphere and provide essential nitrogenous compounds to the plant. This can be a great advantage, as many cycads grow in nutrient-poor habitats.
Conservation
The Eastern Cape dwarf cycad was one of the first three Cape cycads to be declared endangered by the Cape provincial nature conservation authorities. Collectors have seriously depleted numbers in certain areas, particularly in easily-accessible terrain. Large numbers have also been destroyed by conversion of land to agriculture, such as in the HumansdorpHumansdorp
Humansdorp is a small town and surrounding district in the Eastern Cape of South Africa, with a population of around 35,000 . It is part of the Kouga Local Municipality of the Cacadu District. The town is the centre of the district's light industry and farming...
and Albany
Albany, South Africa
Albany, South Africa was a district in the Eastern Cape, South Africa...
districts.
A few viable colonies are protected on state-owned land, and a large colony occurs in the Cape provincial cycad reserve near Grahamstown
Grahamstown
Grahamstown is a city in the Eastern Cape Province of the Republic of South Africa and is the seat of the Makana municipality. The population of greater Grahamstown, as of 2003, was 124,758. The population of the surrounding areas, including the actual city was 41,799 of which 77.4% were black,...
, where plants are regularly inspected. Here, many seedlings can be seen amongst the mature plants, and the species therefore seems to be in no immediate danger of extinction.
E. caffer is classified as Near Threatened (NT) on the International Union for Conservation of Nature's Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
2007, and listed on Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).