Kadua degeneri
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| ( Fosberg ) WL Wagner & Lorence |
Kadua degeneri is a plant from the genus Kadua in the family of the Rubiaceae (Rubiaceae). It is endemic to Hawaii .
description
Vegetative characteristics
Kadua degeneri grows as a branching shrub . The trunks have a square cross-section and are densely hairy or glabrous. The bark of the older trunks flakes off in cork-like layers.
The opposite continuously arranged on the branches leaves are in a petiole and leaf blade divided. The petiole is 0 to 0.2 inches long. The simple, paper-like to slightly leathery leaf blade is 1 to 4 centimeters long and 0.3 to 2 centimeters wide, from lanceolate to ovoid to heart-shaped. The upper side of the leaf blade is glabrous, while the underside is glabrous or finely hairy along the central leaf vein. The base of the spade tapers to a point or is heart-shaped, the tip of the spreader is pointed or pointed and the edge of the spread is entire. Several side veins branch off from each side of the central leaf vein and the higher-order leaf veins form an inconspicuous net-like pattern. The stipules resemble the deciduous leaves, are fused with the base of the petiole and thus form a bald or finely hairy leaf sheath . The lanceolate leaf sheath is 0.25 to 0.28 inches long and has a more or less frayed edge.
Generative characteristics
The terminal, panicle-like , zymous inflorescences are reduced. The inflorescences contain one to ten individual flowers.
The four-fold flowers are radial symmetry . The top-shaped flower cup is 1.5 to 2 millimeters long. The sepals are fused together to form a calyx tube. The leaf-like calyx lobes are lanceolate in shape with a length of 4 to 8 millimeters and a width of 1.5 to 3.5 millimeters. The fleshy and glaucous petals are fused together like a saucer. The corolla tube reaches a length of 0.6 to 0.7 centimeters and has a non-square cross-section. The four crown lobes reach lengths of 0.3 to 0.4 centimeters. The double-lobed stylus is densely hairy at its base.
The capsule fruits are more or less spherical in shape with a length of up to 0.3 centimeters and a thickness of 0.4 to 0.5 centimeters. The endocarp is somewhat lignified. Each of the fruits contains several almost black seeds. They are irregularly shaped and the seed coat has scars.
Occurrence and endangerment
The natural range of Kadua degeneri is on the Hawaiian island of Oahu . The species occurs there in the Waiʻanae mountain range .
Kadua degeneri thrives at altitudes of 365 to 380 meters. The species grows there in dry to moderately moist forests and on steep rock faces located in these forests.
Kadua degeneri is classified as "Critically Endangered" on the IUCN Red List . The coprosmifolia subspecies is also listed as "critically endangered" by the IUCN, but is presumably already extinct, as no living plants have been found since 1980. Displacement by invasive species as well as habitat destruction by introduced and feral animals and forest fires are named as the main endangerment factors. The total stock, which is composed of three populations comprising fewer than 200 fully grown plants , is seen as declining.
Taxonomy
It was first described as Hedyotis degeneri in 1943 by Francis Raymond Fosberg in Bernice P. Bishop Museum Bulletin . Warren L. Wagner and David H. Lorence transferred the species as Kadua degeneri in Systematic Botany in the genus Kadua in 2005 .
There are up to two subspecies:
- Kauda degeneri subsp. coprosmifolia (Fosberg) WL Wagner & Lorence is probably already extinct.
- Kauda degeneri subsp. degeneri is the nominate form .
Individual evidence
- ↑ a b c d e f Kadua degeneri. In: Flora of the Hawaiian Islands. www.botany.si.edu/pacificislandbiodiversity/hawaiianflora, accessed on January 6, 2017 (English).
- ↑ a b c Kadua degeneri in the endangered Red List species the IUCN 2016 Posted by: M. Keir, T. Portner, L. Weisenberger, J. Kwon & VL Caraway, 2016. Retrieved on January 6, 2017th
- ↑ a b Kadua degeneri subsp. coprosmifolia in the endangered Red List species the IUCN 2016 Posted by: M. Keir, T. Portner, L. Weisenberger, J. Kwon & VL Caraway, 2016. Retrieved on January 6, 2017th
- ↑ Kadua degeneri subsp. degeneri in the endangered Red List species the IUCN 2016 Posted by: N. Sugii, JM Yoshioka, M. Keir, L. Weisenberger, J. Kwon & VL Caraway, 2016. Retrieved on January 6, 2017th
- ↑ Kadua degeneri at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed January 6, 2017.
- ↑ Kadua degeneri subsp. coprosmifolia. In: Flora of the Hawaiian Islands. www.botany.si.edu/pacificislandbiodiversity/hawaiianflora, accessed on January 6, 2017 (English).
- ↑ Kadua degeneri subsp. degeneri. In: Flora of the Hawaiian Islands. www.botany.si.edu/pacificislandbiodiversity/hawaiianflora, accessed on January 6, 2017 (English).