Nesogordonia tricarpellata
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Illustration of a branch of the hardening material of Nesogordonia tricarpellata |
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| Nesogordonia tricarpellata | ||||||||||||
| Skema & Dorr |
Nesogordonia tricarpellata is a plant from the family of mallow (Malvaceae). It was first described in 2011 and is endemic to southeastern Madagascar .
description
Appearance and leaf
Nesogordonia tricarpellata grows as a tree that can reach heights of 4 to 8 meters and a diameter of around 15 centimeters at chest height . The bark of the young trunks is bare, light whitish-gray to brown and has noticeable leaf scars. The bark of older trunks is dark brown in color. The curly haired end bud is awl to sickle-shaped with a length of about 3 millimeters.
The alternate leaves arranged on the branches are divided into petioles and leaf blades and are permanent. The leaf stalk, bald or covered with a few tiny star-shaped or with a number of simple hairs ( trichomes ) is 1 to 1.5 centimeters long and not or slightly thickened at the top and at the base; it turns dark brown on drying ( herbarium material ). The somewhat leathery leaf blade is elliptical to narrow-elliptical with a length of 5 to 7.5 centimeters and a width of 2.5 to 3 centimeters with a blunt or rounded blade base and a long tapering and spiky upper end. The slightly bent back edge of the leaf is finely notched. Like the lighter green underside of the leaf, the dark green upper side of the leaf is bare or covered with simple trichomes. The leaf vein is brochidodromic, that is, the side veins do not end at the leaf margin, but rather open like a loop in the next vein. On some axils of the leaf veins there are domatia from egg to circular arranged clusters of upright or curved, simple or star-shaped trichomes, which have a length of 0.6 to 0.9 millimeters and a diameter of 0.5 to 0.6 millimeters . The early falling stipules were not seen by the authors of the first description.
Inflorescence and flower
The pendant, panicles , zymose inflorescence is up to 4.5 centimeters long and contains a rare, usually two or three flowers. The inflorescence stem, up to 2.6 centimeters long, is bare or has a few tiny star-shaped trichomes. The bare or sparsely covered flower stalk with tiny star-shaped trichomes is up to 1.5 centimeters long and is divided 3.2 to 4.3 millimeters below the flower. The short-lived outer chalice was not present in the herbarium material viewed by the authors of the first description.
Specimens with flower buds were collected in February and flowering in June. The flower buds are spherical with a length and a diameter of 3 to 4 millimeters. The hermaphrodite flowers are radially symmetrical and five-fold. The five, with a length of 5 to 5.5 millimeters and a width of 1.7 to 2.2 millimeters, egg-shaped and fleshy sepals are fused together at the base. The inside of the sepals, like the outside, is covered with two types, simple or star-shaped, trichomes. The five white, fleshy, with a length of 3.5 to 4 millimeters and a width of 2 to 2.5 millimeters egg-shaped to elliptical petals are glabrous and somewhat narrowed at the upper end. The androeceum consists of two stamen circles. The outer stamen circle consists of three bundles with two to three fertile stamens each , the stamens of which are fused to up to 0.5 mm in length. The inner circle of stamen consists of three staminodes . The fleshy anthers are with a length of 2.7 to 2.9 millimeters and a width of 0.8 to 1.1 millimeters asymmetrically lanceolate to elongated with a pointed or pointed upper end. Three carpels form the densely with small, approximately 0.15 millimeters by measuring shed covered ovary , having a length and a diameter of about 1.5 millimeters. The two ovules per carpel, angular at their base, are in a central angled placentation . The three fused styles are 2 to 2.5 millimeters long. The scar lobes are about 0.8 millimeters long and fleshy. The upper end of the scar flap is dark red and turns black when dry (herbarium material).
Fruit and seeds
One fruiting specimen was collected in June. The woody, chestnut-brown capsule fruits are inverted-conical with a length of 1.5 to 2 centimeters and a diameter of 1.2 to 1.5 centimeters. The peel is slightly warty and covered with a few scales or short, star-shaped trichomes. The upper end of the fruit is flattened and has a centrally located umbo . There is no edge or it is only sparsely developed. The seeds have a length of 4 to 5 millimeters and a diameter of 3 to 4 millimeters and have a 5 to 10 millimeter long and 4 to 5 millimeter wide wing.
Occurrence
The natural range of Nesogordonia tricarpellata is located in the southeast of Madagascar and is therefore the southernmost of all Nesogordonia species. It is known there from a location in the Andohahela National Park and another location on the lower slopes of the Ivohibe – Bemangidy Forest. The species grows in damp forests at altitudes of 90 to 500 meters.
Systematics
It was first described as Nesogordonia tricarpellata in 2011 by Cynthia Skema and Laurence Joseph Dorr in PhytoKeys number 2, page 10. The specific epithet tricarpellata indicates that there are three free carpels in this species.
According to the authors of the first description, Nesogordonia tricarpellata can be safely assigned to the genus Nesogordonia , even if it differs from the other species of this genus in some morphological properties. For example, the shape of the fruits and seeds are unique to this genus.
literature
- Cynthia Skema, Laurence J. Dorr: Nesogordonia tricarpellata (Dombeyaceae), a new species from Madagascar that compels modification of the morphological circumscription of the genus . In: PhytoKeys . No. 2 , 2011, ISSN 1314-2003 , p. 10-14 , doi : 10.3897 / phytokeys.2.747 .
Individual evidence
- ↑ a b c d e f g h Cynthia Skema, Laurence J. Dorr: Nesogordonia tricarpellata (Dombeyaceae), a new species from Madagascar that compels modification of the morphological circumscription of the genus . In: PhytoKeys . No. 2 , 2011, ISSN 1314-2003 , p. 10-14 , doi : 10.3897 / phytokeys.2.747 .
- ↑ Nesogordonia tricarpellata. In: The International Plant Names Index. www.ipni.org, accessed on March 23, 2013 (English).
