Cryosophila
| Cryosophila | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Cryosophila warscewiczii , inflorescence |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Cryosophila | ||||||||||||
| flower |
Cryosophila is a genus of palm that occurs from Mexico to Colombia. A characteristic feature of the genus are the branched root thorns on the trunk. The palm trees grow in the undergrowth mainly from humid tropical forests of the lower elevations. Half of the ten species are considered endangered.
features
Trunks and root thorns
The representatives of Cryosophila are single-stemmed palms, rarely multi-stemmed. The trunks have long and branched root spines. The trunk is between 0.5 and 15 m high and has a diameter of 4 to 20 cm. In most species, the trunk is straight and upright. Sometimes, especially on hillside locations, the trunk shows a saber growth.
The thorns are modified roots. This was first recognized by Wendland in 1869. They arise endogenously the tribe and have the anatomy of a typical monocots -Wurzel on, such as a polyarches central vascular bundles . As the thorn grows, the root cap falls off, the base tissue becomes sclerotic , and the end of the root differentiates into a sharp point. The distribution of the thorns along the trunk is very variable, but there are two basic patterns: in most species they are most dense and thinner at the lower end of the trunk; in Cryosophila bartlettii , Cryosophila grayumii and Cryosophila kalbreyeri they are rather evenly distributed.
There are two groups of root thorns: “trunk” thorns are directed downwards, rather short and have a round cross-section. "Crown" thorns are rather ascending, long and compressed. They are found between the leaf bases, so they are at the internodes and fall off with the leaves.
The thorns are usually simply branched, sometimes two or three times. The side branches also develop into thorns. The length of the thorns ranges from under 3 cm to over 15 cm, depending on the species.
At the base of the trunk, the adventitious roots do not develop into thorns, but penetrate the ground. A cone of roots often forms at the base.
.jpg)
leaves
The crown is usually formed from 15 to 25 leaves , with a range from 5 to 35. The leaves are arranged in a spiral and form a spreading crown. The leaf stalks are between 40 and 320 cm long and at the narrowest point between 0.6 and 3.3 cm wide. The base of the petiole is split at maturity in all species except Cryosophila . In the case of youth leaves or the youngest leaves, the base is not split. The hastula , the scale-like extension of the petiole beyond the attachment point of the blade, is usually short and triangular.
The leaf blade is folded and shaped like a hand or fan. Along or near the midrib, the leaf is split, so that two leaf halves are formed. This central gap extends to five or less cm from the base of the blade, except for Cryosophila williamsii and Cryosophila cookii . The blade consists of 30 to 80 segments. The central segment is 40 to 160 cm long, but only over a meter in Cryosophila cookii , Cryosophila guagara and Cryosophila macrocarpa . The blade is further divided by two types of gaps: deep primary, adaxial gaps which divide the blade into a number of mostly multi-segmented sections; and less deep secondary crevices.
The underside of the leaf blade is finely haired, the hairs are long and thin-walled. The underside of the leaf therefore appears whitish to silvery.
The central ribs of the leaf segments are large, yellow and very stiff. The stiffness is due to a continuous fiber cylinder that makes up the majority of the rib. This cylinder surrounds a colorless base fabric, in the middle of which one or more large vascular bundles are embedded, usually several small bundles at the edge.
Inflorescences
The inflorescences are between the leaves, each inflorescence grows through the split petiole base of its bract . Only in Cryosophila nana does it grow out from the side of the unsplit petiole. The inflorescences can be ascending, arching or pointing downwards. The main axis of the inflorescence is between 20 and 130 cm long with a diameter of 0.4 to 2.1 cm at the transition from the inflorescence stalk to the inflorescence axis , only with Cryosophila cookii it is up to 3.0 cm thick. The inflorescence stalk is between 10 and 80 cm long, the cover sheet 5 to 25 cm. There are two to ten bracts on the peduncle . These are between 5 and 50 cm long and are wide to narrow oval. The inflorescence axis is between 5 and 70 cm long and thus takes up between a fifth and two thirds of the entire inflorescence length. With the exception of Cryosophila cookii , the inflorescences have 10 to 40 side axes of the first order. Most of the time the lowest side branches themselves are branched twice, the middle branches once and the top branches not. The longest side branches of the first order are 1 to 20 cm long, although they are longer than 7 cm only in Cryosophila stauracantha and Cryosophila warscewiczii . Each side branch of the first order sits in the armpit of a bract . This is broad oval to linear oval. The longest bracts are between 5 and 30 cm long.
The fruit stand is either open, so that the side branches of the first order are visible (in Cryosophila stauracantha and Cryosophila warscewiczii ), or the fruits are so dense that the side branches are not visible (in all other species).
blossoms
The flowers are 2 to 6 mm long and 1.5 to 5 mm wide. They stand individually on short flower stalks 0.1 to 1.5 mm in length. The three ivory-white to cream-colored sepals are half fused together. The three petals are free and of the same color. The Androeceum consists of six stamens , their flat, thin stamens , which are usually fused together over one to three quarters of their length. They are usually 2 to 3 mm long, the anthers 1 to 2.5 mm. The pistil consists of three carpels. The ovary has a diameter of 0.2 mm to 1.4, stylus and scar are together 0.7 to 3.5 mm long.
The flowers are proterogynous : the stigma is ready to receive while the inflorescence is still in the bud stage. The stigmas dry up before the bracts of the peduncle open and before the anthers open. The pollen grains are monosulcat or trichotomosulcat (have a single or three-rayed germ fold). The shape of the pollen grains is elliptical to triangular in polar view, the surface of the exine is reticulate, furrowed reticulate or punctured.
The flowers are very uniform within the genus and, in contrast to most palm genera, hardly offer any features to distinguish the individual species. The flowers of Cryosophila cookii and Cryosophila guagara are usually larger than 4.8 mm, and smaller in the other species.
Fruits and seeds
The fruits are almost spherical to somewhat elongated. Their length ranges from 1.2 to 3.6 cm, their diameter from 1.0 to 2.9 cm. The fruits of Cryosophila macrocarpa are over 3 cm long, those of Cryosophila warscewiczii between 2 and 2.5 cm , the fruits of the other species are smaller than 2 cm. Unripe fruits are green and change to light greenish yellow to ivory or cream colored when ripe. The exocarp is smooth and thin, the mesocarp is somewhat fleshy, the endocarp membranous. The calyx and crown are preserved on the ripe fruits.
The seeds are the same shape as the fruit. Only in Cryosophila williamsii are they very irregularly shaped. They are 0.7 to 2.7 cm long with a diameter of 0.7 to 2.3 cm, the surface is cream to straw-colored.
Distribution, locations and endangerment
The genus is native to Central America. The area extends in the north to Mexico , in the south to the northwest of Colombia . Most species occur disjointly in a linear sequence from north to south. Some species are extremely local endemics .
All species of the genus grow in the undergrowth of forests. Most of them grow in damp to wet lowland forests. The exception is Cryosophila nana , which grows in dry forests. Cryosophila kalbreyeri and Cryosophila stauracantha can also thrive in drier locations. The highest locations are around 1000 m above sea level. Five species are calciphile, so they prefer to grow over limestone, with Cryosophila bartlettii and Cryosophila williamsii only occurring on limestone rocks. The other species - with the exception of Cryosophila nana - are calcifuge, so avoid limestone soils.
In 1995, Evans identified five of the ten species as threatened or endangered : Cryosophila bartlettii, cookii, grayumii, kalbreyeri and C. williamsii . He describes Cryosophila macrocarpa as very rare with an unknown degree of endangerment. The main reason for the threat is the loss of the sites due to the destruction of the rainforest. In his classification for the IUCN from 1998, he classified three of the seven listed species as low endangered ( Cryosophila guagara , Cryosophila kalbreyeri and Cryosophila nana ), Cryosophila bartlettii as endangered, two species as critically endangered ( Cryosophila cookii and Cryosophila grayumii ) . Cryosophila williamsii is extinct in the wild.
.jpg)
.jpg)
Systematics
The genus Cryosophila flower is placed within the family Arecaceae in the subfamily Coryphoideae , tribe Cryosophileae .
Randall J. Evans accepted 10 species in his generic monograph in 1995. These were adopted in 2005 by Rafael Govaerts and John Dransfield in their World Checklist of Palms .
- Cryosophila bartlettii R.J. Evans : Home is Panama.
- Cryosophila cookii Bartlett : The home is Costa Rica.
- Cryosophila grayumii R.J. Evans : The home is Costa Rica.
- Cryosophila guagara P.H.Allen : The home is Costa Rica and western Panama.
- Cryosophila kalbreyeri (Dammer ex Burret) Dahlgren : The home is the southeast of Panama and Colombia. It occurs in two subspecies.
- Cryosophila macrocarpa R.J. Evans : The home is the Departamento del Chocó in Colombia.
- Cryosophila nana (Kunth) Blume : The home is western and southern Mexico.
- Cryosophila stauracantha (Heynh.) RJEvans : The distribution area extends from southeast Mexico to Honduras.
- Cryosophila warscewiczii (H. Wendl.) Bartlett : The home is Costa Rica, Honduras, Nicaragua and Panama.
- Cryosophila williamsii P.H. Allen : The home is Honduras.
The cladistic analysis of morphological features by Evans resulted in the following strict consensus tree :
|
|
|
||||||||||||||||||||||||||||||||||||||||||||||||
|
|
The name Cryosophila means cold-loving. The meaning is unknown, especially since all species are sensitive to cold.
Research history
Cryosophila nana was described as the first species that is now included in the genus, but initially placed in what is now purely an ancient world: Corypha (as Corypha nana HBK) or Chamaerops (as Chamaerops mocini HBK). Carl Ludwig Blume established the genus Cryosophila in 1838 or 1839 , to which he only counted Cryosophila nana . Wendland described the same species again in 1869 under the name Acanthorrhiza aculeata in a new genus, this was recognized by Bartlett in 1935, also that Kunth had described the same species twice. Bartlett described three new species in 1935, and Allen described two more in 1953. However, the identification keys of the last two authors did not allow a clear identification of the species. Moore published a comprehensive description of the generic characteristics in 1972, which was essentially adopted by Uhl and Dransfield in 1987. The first monograph on the genus with a revision of the species was published by RJ Evans in 1995.
supporting documents
- Randall J. Evans: Systematics of Cryosophila (Palmae) . Systematic Botany Monographs, Volume 46, 1995, pp. 1-70. (JSTOR)
Individual evidence
- ↑ Cryosophila guagara in the IUCN Red List of Threatened Species . Retrieved September 12, 2009.
- ↑ Cryosophila kalbreyeri in the IUCN Red List of Threatened Species . Retrieved September 12, 2009.
- ^ Cryosophila nana in the IUCN Red List of Threatened Species . Retrieved September 12, 2009.
- ↑ Cryosophila bartlettii in the IUCN Red List of Threatened Species . Retrieved September 12, 2009.
- ↑ Cryosophila cookii in the IUCN Red List of Threatened Species . Retrieved September 12, 2009.
- ↑ Cryosophila grayumii in the IUCN Red List of Threatened Species . Retrieved September 12, 2009.
- ↑ Cryosophila williamsii in the IUCN Red List of Threatened Species . Retrieved September 12, 2009.
- ^ John Dransfield, Natalie W. Uhl, Conny B. Asmussen, William J. Baker, Madeline M. Harley, Carl E. Lewis: A New Phylogenetic Classification of the Palm Family, Arecaceae . Kew Bulletin, Vol. 60, 2005, pp. 559-569. (JSTOR)
- ↑ Rafaël Govaerts (ed.): Cryosophila. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved August 27, 2009.
- ^ Robert Lee Riffle, Paul Craft: An Encyclopedia of Cultivated Palms , 4th Edition, Timber Press, Portland 2007, ISBN 978-0-88192-558-6 , p. 316.
Web links
- Cryosophila on the homepage of the Fairchild Tropical Botanic Garden