Pholidostachys

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Pholidostachys
Pholidostachys dactyloides

Pholidostachys dactyloides

Systematics
Commelinids
Order : Palm- like arecales
Family : Palm family (Arecaceae)
Subfamily : Arecoideae
Tribe : Geonomateae
Genre : Pholidostachys
Scientific name
Pholidostachys
H. Wendl. ex Hooker f.

Pholidostachys is a genus of palm that is native to Central and South America. Their representatives are small to medium-sized, pinnate-leaved palms with conspicuously long, slender petioles.

features

The representatives are single-stemmed. Only Pholidostachys pulchra forms several trunks. With the exception of one species, the trunks are erect, 1 to 11 m high and 3 to 22 cm thick. In Pholidostachys panamensis the stems are shorter and partly prostrate.

The number of chromosomes is unknown.

leaves

A trunk has 4 to 17 leaves , the average is 14. The leaf sheaths are slightly open, no crown shaft is formed. The leaf sheaths are mostly fibrous on the edge. The petiole is well developed. The average length per species ranges from 51.7 to 102.1 cm. The rachis is well developed in all species, the average length here ranges from 42.0 to 192.4 cm. The leaves are pinnate, never undivided. There are 3 to 18 leaflets on each side of the throat. These are of equal or unequal width and are arranged regularly. The leaf shape of the pinna is mostly lanceolate to slightly sigmoidal. Often the pinnate base is contracted and folded. The feather tip is long and pointed.

Inflorescences

There are different types of inflorescences in the genus : the inflorescence can be branched once with an elongated inflorescence stalk , a short inflorescence axis and several rachillae hanging to the flower (flower-bearing axes); it can be branched once or twice with a well-developed stem and axis and several rachillae protruding towards the flower; it can be branched once or rarely twice with a well-developed stalk, short axis and several upright rachillae; it can be spike-shaped with a well-developed stalk, a missing axis and a curved or upright rachilla.

The inflorescence forms are different forms of bracteoles and bracts along the peduncle. In Pholidostachys dactyloides , the rachillae are completely enclosed by the fibrous bracts during flowering. In most other species, the bracts are woody and do not cover the rachillae to bloom.

The flower pits on the rachillae are covered by lips, the shape of which is taxonomically important. They can be irregularly shaped, often pointed or pointed and completely cover the pit before flowering; they can be regularly shaped, rounded and completely cover the pit before flowering; or they are regularly shaped, rounded and do not cover the pits.

The flowers are in triads, at least in the lowest areas of the rachillae. The upper areas usually only have male flowers.

blossoms

The male flowers consist of three free, narrow sepals , three valvaten , short fused together at the base of petals and six stamens . The filaments are almost entirely fused into a tube, but the tip is free. This free part is short and triangular, but two types are linear and inflected.

The female flowers have similar sepals and petals. They have a staminode tube with lobed tips. For flowering these tips are spread out in a star shape. The stylus is extended with three protruding scars .

The inflorescences of all kinds are likely to be proterandric . Nothing is known about pollination . Different pollinators can be used depending on the structure of the inflorescences.

Fruits and seeds

The fruits have different shapes, but all have basal scar remains. The shape can be compressed, obovate in side view with an asymmetrical base, ellipsoidal in front view, with a distinct longitudinal rib on one side and several small ribs on the opposite side; with the same shape, there can only be one clearly meridional longitudinal rib; the fruit can hardly be compressed, obovate, with indistinct longitudinal ribs; it can be broadly obovate, with a distinct longitudinal rib; or barely compressed, ellipsoidal and with an indistinct longitudinal rib.

Distribution and locations

The distribution area of Pholidostachys extends from Nicaragua in the north to Peru and Brazil in the south. Most species occur in Colombia with six species. The sites range from sea level to 1750 m above sea level, although the majority of the finds come from lower areas. The species all colonize similar locations. They mainly grow in the lowland or mountain rainforest on non-flooded areas, only rarely on flooded areas.

They grow in the undergrowth of the tropical rainforests.

Systematics

Pholidostachys H. Wendl. ex Hook.f. is classified within the palm family (Arecaceae) in the subfamily Arecoideae , Tribus Geonomateae . She is a monophyletic group . Her sister group is Welfia .

Internal system

In the World Checklist of Selected Plant Families of the Royal Botanic Gardens, Kew , the following types are recognized:

Botanical history

The genus was first described by Joseph Dalton Hooker in 1883 and attributed to Hermann Wendland . Type species is Pholidostachys pulchra . Wessels Boer recognized three species in his genus revision in 1968. The next revision by Andrew Henderson in 2012 showed eight species with a much broader data base (288 versus 16 herbarium specimens). This view was also followed by the World Checklist of Selected Plant Families at the Royal Botanic Gardens, Kew .

supporting documents

  • 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. 473-475.
  • Andrew Henderson: A revision of Pholidostachys (Arecaceae) . Phytotaxa 43, 2012, pp. 1-48.

Individual evidence

  1. a b c d e f g h i j k Andrew Henderson: A revision of Pholidostachys (Arecaceae) . Phytotaxa 43, 2012, pp. 1-48.
  2. ^ A b 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. 473-475.
  3. Rafaël Govaerts (ed.): Pholidostachys. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved July 8, 2013.

Web links

Commons : Pholidostachys  - collection of images, videos and audio files