34-487: Encephalartos is a genus of cycad native to Africa. Several species of Encephalartos are commonly referred to as bread trees , bread palms or kaffir bread , since a bread-like starchy food can be prepared from the centre of the stem. The genus name is derived from the Greek words en (within), kephalē (head), and artos (bread), referring to the use of the pith to make food. They are, in evolutionary terms, some of
68-429: A number of differences between cycads and palms. For one, both male and female cycads are gymnosperms and bear cones (strobili), while palms are angiosperms and so flower and bear fruit. The mature foliage looks very similar between both groups, but the young emerging leaves of a cycad resemble a fiddlehead fern before they unfold and take their place in the rosette, while the leaves of palms are just small versions of
102-427: A period of about twenty-eight days before reaching maturity. All life stages after the crawler stage feed on the host plant by piercing the epidermis and sucking sap. Crawlers often get carried away by the wind, landing on neighbouring plants and infesting them. In a heavy infestation, the fronds of cycads become covered with a thick white layer of scale insects. Even when the adult insects die, they remain attached to
136-595: A stout and woody ( ligneous ) 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. Cycads vary in size from having trunks only a few centimeters to several meters tall. They typically grow slowly and have long lifespans. Because of their superficial resemblance to palms or ferns , they are sometimes mistaken for them, but they are not closely related to either group. Cycads are gymnosperms (naked-seeded), meaning their unfertilized seeds are open to
170-404: A time. Female cones are borne singly, or up to three at a time, and may weigh up to 60 pounds (27 kg). In some species, male cones with ripe pollen emit a nauseating odour. When the pollen has been shed and the males cones decay, a strong odour of acetic acid has also been noted. Colonies of the cyanobacterium Nostoc punctiforme occur in apparent symbiosis inside the root tissue, while
204-607: Is known from the latest Carboniferous-Early Permian of South Korea and China, such as Crossozamia . Unambiguous fossils of cycads are known from the Early-Middle Permian onwards. Cycads were generally uncommon during the Permian. The two living cycad families are thought to have split from each other sometime between the Jurassic and Carboniferous. Cycads are thought to have reached their apex of diversity during
238-446: Is one of their food plants. They include the leopard magpie (most Encephalartos spp., other cycads, etc.), Millar's tiger (cultivated E. villosus ), dimorphic tiger (cycads under forest canopy), spotted tigerlet ( E. villosus ), inflamed tigerlet ( E. villosus ), Staude's tigerlet ( E. ngoyanus , cultivated E. villosus and Stangeria ) and pallid grey ( E. natalensis ). In cultivation various scale insects attack
272-403: Is the accumulation of toxins in seeds and vegetative tissues; through horizontal gene transfer , cycads have acquired a family of genes ( fitD ) from a microbial organism, most likely a fungus, which gives them the ability to produce an insecticidal toxin. Cycads all over the world are in decline, with four species on the brink of extinction and seven species having fewer than 100 plants left in
306-516: The Yolngu in Australia's Arnhem Land as a source of food. They are harvested on their dry season to leach its poison under water overnight before ground into a paste, wrapped under bark and cooked on open fire until done. In Vanuatu , the cycad is known as namele and is an important symbol of traditional culture. It serves as a powerful taboo sign, and a pair of namele leaves appears on
340-523: The cycad scale , the sago palm scale , and the Asian cycad scale . This is a serious pest of cycads which can kill its host plant. The adult female cycad aulacaspis scale has a flattened, circular or pear-shaped cover, often distorted in shape by the close proximity of leaf veins or other scale insects. The cover is white, and may be translucent enough to see the orange coloured insect with its orange eggs beneath. White or pale yellow shed skins are seen on
374-469: The national flag and coat of arms. Together with the nanggaria plant, another symbol of Vanuatu culture, the namele also gives its name to Nagriamel , an indigenous political movement. Aulacaspis yasumatsui Aulacaspis yasumatsui , or cycad aulacaspis scale ( CAS ), is a scale insect species in the genus Aulacaspis that feeds on cycad species such as Cycas revoluta or Dioon purpusii (Purpus' cycad). Other common names include
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#1732766224161408-610: The Mesozoic. Although the Mesozoic is sometimes called the "Age of Cycads," some other groups of extinct seed plants with similar foliage, such as Bennettitales and Nilssoniales , that are not closely related, may have been more abundant. The oldest records of the modern genus Cycas are from the Paleogene of East Asia. Fossils assignable to Zamiaceae are known from the Cretaceous, with fossils assignable to living genera of
442-431: The air to be directly fertilized by pollination , as contrasted with angiosperms , which have enclosed seeds with more complex fertilization arrangements. Cycads have very specialized pollinators , usually a specific species of beetle . Both male and female cycads bear cones ( strobili ), somewhat similar to conifer cones . Cycads have been reported to fix nitrogen in association with various cyanobacteria living in
476-452: The diverse genus Encephalartos in southern and central Africa, and Macrozamia in Australia. Thus, the distribution pattern of cycad species with latitude appears to be an artifact of the geographical isolation of the remaining cycad genera and their species, and perhaps because they are partly xerophytic rather than simply tropical . Nuts of the Cycas orientis ( nyathu ) are coveted by
510-546: The early Carboniferous . Cycads Ginkgo Conifers Bennettitales Gnetales Angiosperms Cycads Ginkgo Conifers Gnetophytes (flowering plants) Cycas Dioon Macrozamia Lepidozamia Encephalartos Bowenia Ceratozamia Stangeria Zamia Microcycas Classification of the Cycadophyta to the rank of family. The following extinct cycad genera are known: The oldest probable cycad foliage
544-575: The extant cycads peaks at 17˚ 15"N and 28˚ 12"S, with a minor peak at the equator . There is therefore not a latitudinal diversity gradient towards the equator but towards the Tropic of Cancer and the Tropic of Capricorn . However, the peak near the northern tropic is largely due to Cycas in Asia and Zamia in the New World, whereas the peak near the southern tropic is due to Cycas again, and also to
578-1141: The family known from the Cenozoic. The living cycads are found across much of the subtropical and tropical parts of the world, with a few in temperate regions such as in Australia. The greatest diversity occurs in South and Central America . They are also found in Mexico , the Antilles , southeastern United States , Australia , Melanesia , Micronesia , Japan , China , Southeast Asia , Bangladesh , India , Sri Lanka , Madagascar , and southern and tropical Africa , where at least 65 species occur. Some can survive in harsh desert or semi-desert climates ( xerophytic ), others in wet rain forest conditions, and some in both. Some can grow in sand or even on rock , some in oxygen-poor, swampy, bog -like soils rich in organic material . Some are able to grow in full sun, some in full shade, and some in both. Some are salt tolerant ( halophytes ). Species diversity of
612-415: The leaves of the genus. These include cycad aulacaspis scale , zamia scale and latania scale . The genus was named by German botanist Johann Georg Christian Lehmann in 1834. All cycads except Cycas had been regarded as members of the genus Zamia until then, and some botanists continued to follow this line for many years after Lehmann had separated Encephalartos as a separate genus. His concept
646-450: The main trunks are up to 10 feet (3.0 m) high, and several of them may be united at a base where a former main trunk once grew. The persistent, pinnate leaves are arranged in a terminal spreading crown, or ascending. The rigid leaflets are variously spiny or incised along their margins. The leaflets have a number of parallel veins and no central vein. The chromosome count is 2n=18. Male cones are elongated, and three or four may appear at
680-461: The margin of the cover. The adult male has an elongated cover with parallel sides; it is white and felted, with shed skins similar in colour to the female. In light infestations, these scales are on the undersides of the leaves, but in heavier infestations they also occur on the upper surface and on the roots, at depths down to about 60 cm (24 in). The cycad aulacaspis scale is native to tropical and sub-tropical parts of southeastern Asia. It
714-411: The mature frond. Another difference is in the stem . Both plants leave some scars on the stem below the rosette where there used to be leaves, but the scars of a cycad are helically arranged and small, while the scars of palms are a circle that wraps around the whole stem. The stems of cycads are also in general rougher and shorter than those of palms. The two extant families of cycads all belong to
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#1732766224161748-429: The most primitive living gymnosperms . All the species are endangered, some critically, due to their exploitation by collectors and traditional medicine gatherers. The whole genus is listed under CITES Appendix I which prohibits international trade in specimens of these species except for certain non-commercial motives, such as scientific research. Several of the species possess stout trunks. In E. cycadifolius ,
782-654: The order Cycadales , and are the Cycadaceae and Zamiaceae (including Stangeriaceae ). These cycads have changed little since the Jurassic in comparison to some other plant divisions. Five additional families belonging to the Medullosales became extinct by the end of the Paleozoic Era. Based on genetic studies, cycads are thought to be more closely related to Ginkgo than to other living gymnosperms. Both are thought to have diverged from each other during
816-475: The rootlets produce root tubercles at ground level which harbour a mycorrhizal fungus of uncertain function, which is however suspected to facilitate the capturing of nitrogen from the air. In several species the pith of the trunk contains a copious amount of high quality starch below the crown. This was formerly cut out by native people as food. Thunberg recorded around 1772 that the Hottentots removed
850-467: The roots (the "coralloid" roots). These photosynthetic bacteria produce a neurotoxin called BMAA that is found in the seeds of cycads. This neurotoxin may enter a human food chain as the cycad seeds may be eaten directly as a source of flour by humans or by wild or feral animals such as bats, and humans may eat these animals. It is hypothesized that this is a source of some neurological diseases in humans. Another defence mechanism against herbivores
884-419: The same form on the leaflet as the leaflets do on the stalk. Due to superficial similarities in foliage and plant structure, cycads and palms are often mistaken for each other. They also can occur in similar climates. However, they belong to different phyla and as such are not closely related. The similar structure is the product of convergent evolution . Beyond those superficial resemblances, there are
918-449: The stalk, perpendicular to it. The leaves are typically either compound (with leaflets emerging from the leaf stalk as "ribs"), or have edges ( margins ) so deeply cut ( incised ) so as to appear compound. The Australian genus Bowenia and some Asian species of Cycas, like Cycas multipinnata , C. micholitzii and C. debaoensis , have leaves that are bipinnate , the leaflets each having their own subleaflets, growing in
952-422: The stem's pith at the crown and buried it wrapped in animal skin for about two months, after which they recovered it for kneading into bread, whence the vernacular name "broodboom" (i.e. bread tree). The burial of the pith apparently facilitated its fermentation and softening, and the dough was lightly roasted over a coal fire. In 1779 Paterson likewise found that the pith of a "large palm" near King William's Town
986-409: The top and center of the crown. The trunk may be buried, so the leaves appear to be emerging from the ground, so the plant appears to be a basal rosette . The leaves are generally large in proportion to the trunk size, and sometimes even larger than the trunk. The leaves are pinnate (in the form of bird feathers, pinnae ), with a central leaf stalk from which parallel "ribs" emerge from each side of
1020-414: The wild. Cycads have a cylindrical trunk which usually does not branch . However, some types of cycads, such as Cycas zeylanica , can branch their trunks. The apex of the stem is protected by modified leaves called cataphylls . Leaves grow directly from the trunk, and typically fall when older, leaving a crown of leaves at the top. The leaves grow in a rosette form, with new foliage emerging from
1054-463: Was contained and eradicated by intensive treatment. This scale is restricted in host range to Cycas , Dioon , Encephalartos , Macrozamia , Microcycas and Stangeria , but of these, it seems to have a preference for Cycas . Adult females lay one hundred or more eggs and these hatch in eight to twelve days. The first instar stage has legs and is known as a "crawler". The juveniles then develop through several other instar stages over
Encephalartos - Misplaced Pages Continue
1088-847: Was first described in 1977 by Tagaki in Thailand, and its range also includes Singapore, Malaysia and China, and it is also known from the Cayman Islands, Puerto Rico and the US Virgin Islands. More recently, it was first detected in Florida in 1996 and had spread to Hawaii by 2000. It was discovered at the National Botanical Research Institute at Lucknow in India in 2007, on Microcycas calocoma , an endangered species of cycad; this infestation
1122-2472: Was originally much broader than the one accepted today, including also the Australian plants we now know as Macrozamia and Lepidozamia . E. gratus Prain (Mulanje cycad) E. humilis Verd. (Dwarf cycad) E. concinnus Dyer & Verdoorn (Runde cycad) E. pterogonus Dyer & Verdoorn (Toothed-cone cycad) E. relictus Hurter E. transvenosus Stapf & Burtt Davy (Modjadji's palm) E. trispinosus (Hooker 1861) Dyer (Bushman's River cycad) E. marunguensis Devred (Marungu cycad) E. brevifoliolatus Vorster (Escarpment cycad) E. striatus Stapf & Burtt Davy E. septentrionalis Schweinfurth ex Eichler (Nile cycad) E. hirsutus Hurter (Venda cycad) E. kanga Pócs & Luke (Mnanasi pori) E. arenarius Dyer (Alexandria/dune cycad) E. laurentianus De Wild. (Kwango giant cycad) E. paucidentatus Stapf & Burtt Davy (Barberton cycad) E. turneri Lavranos & Goode (Turner's cycad) E. munchii Dyer & Verdoorn (Munch's cycad) E. afer (Thunberg 1775) Lehmann (Eastern Cape dwarf cycad) E. macrostrobilus Scott Jones & Wynants E. horridus (Von Jacquin) Lehmann (Eastern Cape blue cycad) E. lehmannii Lehmann (Karroo cycad) E. villosus Lemaire (Poor man's cycad) E. msinganus Vorster (Msinga cycad) E. natalensis Dyer & Verdoorn (Natal giant cycad) E. woodii Sander (Wood´s cycad) E. longifolius (von Jacquin) Lehmann (Thunberg's cycad, Broodboom) E. friderici-guilielmi Lehmann (White-haired cycad) E. ghellinckii Lemaire (Drakensberg cycad) E. chimanimaniensis Dyer & Verdoorn (Chimanimani cycad) E. sclavoi De Luca, Stevenson & Moretti (Sclavo's cycad) E. equatorialis Hurter E. ituriensis Bamps & Lisowski (Ituri Forest cycad) E. dyerianus Lavranos & Goode (Lillie cycad) E. nubimontanus Hurter (Blue cycad) E. cupidus Dyer (Blyde River cycad) E. dolomiticus Lavranos & Goode (Wolkberg cycad) E. eugene-maraisii Verd. (Waterberg cycad, Bergpalm) E. tegulaneus Melville (Kenyan giant cycad) Cycad Cycads / ˈ s aɪ k æ d z / are seed plants that typically have
1156-654: Was utilised by the Africans and Hottentots as bread. The pith was removed and left till sourish, before it was kneaded into bread. Their large seeds consist of an often poisonous kernel covered by an edible fleshy layer. Female cones are consequently destroyed by baboons , as they relish the pith around the seeds. Vervet monkeys , rodents and birds also feed on the seeds, but due to their unpredictable toxic qualities they are not recommended for human consumption. The early larval instars of some aposematic , day-flying looper moths are specific to cycads, and genus Encephalartos
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