Allagoptera
| Allagoptera | ||||||||||||
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| Allagoptera | ||||||||||||
| Nees |
Allagoptera is a palm genus native to South America. They grow on dry locations and are characterized by their mostly creeping habit and their spike-shaped inflorescences.
features
The representatives are small, trunkless or moderately large, upright palms. They are single-stemmed or multi-stemmed, reinforced or unreinforced, but always flowering several times and single-sexed separately ( monoecious ). The trunk is erect or very short and underground. Sometimes it is dichotomously branched. It is rough and densely covered with ring-shaped leaf scars.
The chromosome number is 2n = 32.
leaves
The leaves are pinnate and marzescent (they remain on the plant after they have died). The leaf sheath is short to long, tubular and adaxially tearing when young. It becomes woody or fibrous. At the base of the petiole it is slightly expanded. The petiole is short to long, slender to strong, deeply furrowed adaxially, rounded abaxially, or triangular in cross section. The surface of the stem is smooth or covered with scales. The leaflets are simply folded and sit regularly or in groups. They are long, narrow, narrowed towards the end, with a pointed end or bilobed and split apically. The midrib can be seen on the top and bottom. It is glabrous or frosted on both sides, or silvery on the underside.
Inflorescences
The inflorescences are single and between the leaves (interfoliar). They are upright or hanging, as well as unbranched. The peduncle is short to very long and circular in cross section. The cover sheet is tubular, thin, flattened dorsiventrally, laterally two-keeled, glabrous or scaly. It becomes fibrous over time and opens up at the top. There is a bract on the peduncle. This is long, slender at the base so that it appears almost stalked, then inflated further up and ending in a beak at the end. It is woody, a little folded and tears open abaxially. The inflorescence axis bears flower triads close together on the lower half and paired male flowers further up . The male flowers are shed early, creating a long, free, pointed end of the inflorescence. The bracts that carry the triads are oval, pointed; the bracts of the male flower pairs have a longer tip. The bracts are laterally fused with the inflorescence axis and also with the bases of the neighboring bracts. The bracts of the single flowers are inconspicuous.
blossoms
The male flowers are large, asymmetrical, ovate or obovate, and angular. In the triads they sometimes stand on long, flat stems that curve around the female flower. The distal, paired flowers are sessile. The three sepals are narrow, fused over the lower quarter of their length, then protruding far. They are pointed, keeled, the edges are whole or notched. The three petals are free, irregular, angular, triangular, valvate and slightly longer than up to four times as long as the calyx. The tips of the petals are slightly thickened. There are 6 to around 100 stamens . The filaments are awl-shaped, united at the base, erect, sometimes flexible and bent in various ways. The anthers are somewhat irregular, short to long, curved but not curved, and dorsifix near the base of the pronounced connective, or near the center. The anthers are latrors or intrors. The rudiment of the pistil is absent or is slender, conical and half as long as the stamens.
The pollen is ellipsoidal, but can also be elongated and / or pear-shaped. Usually it is slightly to clearly asymmetrical. The germ opening is a distal sulcus. The longest axis measures 20 to 50 micrometers.
The female flowers are spherical and smaller or slightly larger than the male. The three sepals are free and broadly imbricat , only the tips are valvat in the bud. The three petals are free, about the same length as the sepals and broadly imbricat, the tips valvat. The staminodes have grown together to form a low, flat-lobed cup. The gynoeceum is ovate or obovate, triple with three ovules . The stigmas are narrow and bent backwards between the tips of the petals to flower. The ovules attach laterally and are anatropic.
Fruits and seeds
The fruit is obovate, squashed by the tightly packed arrangement, and greenish-yellow to brown in color. She is mostly lonely. The scars remain on the fruit as an apical button, the flower envelope is enlarged and persistent. The exocarp is smooth or covered with scales. The mesocarp is fibrous and fleshy. The endocarp is hard and thin, or thick and bony, smooth, with three germ pores near the base. There are three broad, shiny lines on the inside.
The seed is obovate or oblong and starts at the base. The umbilicus (hilum) is small, the raphe is wide with large, curved and small anastomosing branches. The endosperm is hard, a central cavity may or may not be present. It is homogeneous or grooved flat (ruminat).
Distribution and locations
Allagoptera occurs in the northeast of Argentina (provinces Misiones and San Pedro), up to the east-central and north-western areas of Bolivia : departments of La Paz , Beni and Santa Cruz . In Brazil , the genus occurs in the coastal areas of the east and southwest: Bahia , Federal District , Espírito Santo , Goiás , South and Central Mato Grosso , Minas Gerais , Paraná , Rio de Janeiro and São Paulo . In Paraguay it occurs in the central and northeastern area: Amambay , Canindeyú , Concepción and Cordillera . The area extends from about the 11th to the 39th parallel south.
However, Dransfield and colleagues only state Brazil and Paraguay as distribution areas.
The representatives grow in lowland regions from sea level to about 1200 m above sea level. They populate savannahs, slopes and hilltops. They also grow on the edges of islands of evergreen forest and in xerophytic forests. Characteristic soils are sandy or rocky, always well drained.
The main occurrences are in two types of vegetation: in the savannah ( campos cerrados ) and in coastal dunes. The Cerrado region is influenced by the extremely dry climate of the Caatinga , which is becoming more humid in south-central Brazil. The western part of the Cerrado includes the dry forests of the Gran Chaco . Allagoptera arenaria forms dense populations in the coastal dunes in eastern Brazil, these areas are known locally as restingas .
ecology
Germination and growth
The germination of allagoptera done "remote tubular": the young plant is connected to the seeds over a long-tube cotyledon-petiole, a Ligula missing. The eophyll is undivided or briefly bifid.
After germination, the seedling takes on a plagiotropic growth form, after a certain short or long growth phase the palm then grows upright. As a young plant, Allagoptera brevicalyx has strongly contractile roots .
Later the trunk grows just below the soil surface and forms several above-ground shoots. All side buds form inflorescences, with the exception of the lowest. The architecture of Allagoptera is composed of orthotropic (vertical) and plagiotropic (horizontal) shoot axes. The axes branch dichotomously. Otherwise they do not form any vegetative side axes.
Phenology
The inflorescences are proterandric . In the populations there are blooming and fruiting individuals at the same time. The flowering times differ slightly between the species. Even within the species, the time of blooming depends on the geographical distribution, the microclimate and soil factors.
In Allagoptera arenaria , the flowering and fruiting phases occur simultaneously and throughout the year; in northeastern Brazil, both phases are concentrated in December and January. The same applies to the other species, whereby the reproductive phases are concentrated in the main rainy seasons or in times of smaller rainfall during the dry months.
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Pollination and Spread
The pollination mechanisms in Allagoptera are little known. The yellowish inflorescences are typical for pollination by bees , beetles and flies . The trunkless habitus in the undergrowth is typical for pollination by flies. Bees and ants as well as beetles of the genus Andranthobius ( Curculionidae ) have been observed in the flowers of Allagoptera leucocalyx . Allagoptera arenaria shows features of the wind - like the insect pollination , here insects of the orders beetles, hymenoptera and butterflies are involved. A. arenaria can self-pollinate (is self-compatible), but is normally cross-pollinated in nature.
The fruits spread through indirect zoochory : In Allagoptera brevicaulyx, beetles bury fruits and seeds to lay their eggs in them. In Allagoptera arenaria beetles of the species Ateuchus squalidus ( Scarabaeidae ) do this . Another variation of the spread discussed is the spread by nocturnal mammals, especially rodents and marsupials of the Restinga vegetation ( e.g. Proechimys ihering , Akodon sp., Metachirus nudicaudatus , Philander opossum and Didelphis aurita ).
Systematics
The genus Allagoptera Nees is placed within the palm family in the subfamily Arecoideae , Tribus Cocoseae and Subtribus Attaleinae. The genus is monophyletic . The exact relationship to the other representatives of the subtribes has not been clarified: one work sees Allagoptera as a sister family of a group from Attalea , Lytocaryum and Syagrus , another as a sister to Cocos and Attalea , but both with little statistical coverage.
In the World Checklist of Selected Plant Families of the Royal Botanic Gardens, Kew , the following types are recognized:
- Allagoptera arenaria (Gomes) Kuntze (Syn .: Allagoptera pumila Nees ): The homeland is Brazil from the state of Sergipe to eastern Paraná .
- Allagoptera brevicalyx M.Moraes : The home is Brazil from the state of Sergipe to northeastern Bahia .
- Allagoptera campestris (Mart.) Kuntze : The home is Brazil, Paraguay and the province of Misiones in Argentina.
- Allagoptera caudescens (Mart.) Kuntze : The homeland is eastern Brazil.
- Allagoptera leucocalyx (Drude) Kuntze : The home is Brazil, Bolivia, Paraguay and the province of Misiones in Argentina.
- Allagoptera robusta R.C. Martins & Filg. : The species first described in 2015 occurs in Brazil.
Allagoptera was first described by Nees von Esenbeck in 1821 . The type is Allagoptera pumila Nees (= Allagoptera arenaria (Gomes) Kuntze ).
The assignment of Allagoptera caudescens to Allagoptera is accepted in Genera Palmarum (2008), Flora Brasiliens (2010) and R. Govaerts.
The genus is unknown to fossil.
use
The fruits of Allagoptera campestris are edible. The endosperm of the fruit is used on the one hand to lower fever, and on the other hand to dye fabrics. The root of Allagoptera arenaria is reddish brown, edible and has a sweet taste. The leaves of this type are used to make fibers for ropes and the leaves are made into baskets. Drinks are made from the mesocarp of the fruit. The fruits of Arenaria leucocalyx , more precisely mesocarp and seeds, are also edible.
The two species Allagoptera arenaria and Allagoptera leucocalyx are often used as ornamental plants .
literature
- John Dransfield, Natalie W. Uhl, Conny B. Asmussen, William J. Baker, Madeline M. Harley, Carl E. Lewis: Genera Palmarum. The Evolution and Classification of Palms . Second edition, Royal Botanic Gardens, Kew 2008, ISBN 978-1-84246-182-2 , pp. 410-413.
- Mónica Moraes R .: Allagoptera (Palmae) . Flora Neotropica, Volume 73. The New York Botanical Garden, New York 1996, ISBN 0-89327-410-0 (JSTOR)
Individual evidence
- ↑ a b c d e f g h i j k l m n John Dransfield, Natalie W. Uhl, Conny B. Asmussen, William J. Baker, Madeline M. Harley, Carl E. Lewis: Genera Palmarum. The Evolution and Classification of Palms . Second edition, Royal Botanic Gardens, Kew 2008, ISBN 978-1-84246-182-2 , pp. 410-413.
- ↑ a b c d e f g h i j k Mónica Moraes R .: Allagoptera (Palmae) . Flora Neotropica, Volume 73. The New York Botanical Garden, New York 1996, ISBN 0-89327-410-0 (JSTOR)
- ↑ a b c d e f g h Rafaël Govaerts (Ed.): Allagoptera. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved August 5, 2018.
