Kadua coriacea
| Kadua coriacea | ||||||||||||
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Kadua coriacea |
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| ( Sm. ) WL Wagner & Lorence |
Kadua coriacea is a plant from the genus Kadua in the family of the Rubiaceae (Rubiaceae). It is endemic to Hawaii .
description
Vegetative characteristics
Kadua coriacea grows as a small upright shrub . The trunks have a round to slightly ribbed cross section and are glabrous or hairy in the upper area.
The opposite continuously arranged on the branches leaves are in a petiole and leaf blade divided. The petiole is 0.5 to 1 centimeter long. The simple, slightly leathery leaf blade is 3 to 8 centimeters long and 0.7 to 3 centimeters wide and is elliptical to elongated, and more rarely ovoid to lanceolate. The upper side of the leaf blade is glabrous, more rarely hairy with bristles, while the underside is glabrous or finely hairy with bristles. The spreader base is wedge-shaped or rounded, the tip of the spreader is blunt and the edge of the spreader is entire. Several lateral nerves branch off from each side of the leaf central nerve, which form a conspicuous, net-like pattern on the underside of the leaf. The stipules resemble the deciduous leaves, are fused with the base of the petiole and thus form a spiky-tipped leaf sheath . The triangular leaf sheath is up to 0.3 inches long and has a pointed spike tip.
Generative characteristics
The terminal, panicle-like , zymous inflorescences usually have a few smaller lateral zymous inflorescences. The inflorescences contain several individual flowers.
The four-fold flowers are radial symmetry . The top-shaped flower cup is about 0.5 millimeters long. The sepals are fused together to form a calyx tube. The leaf-like calyx lobes are triangular in shape with a length of 0.5 to 0.7 millimeters. The fleshy, bald or finely hairy petals are fused together like a salver. The corolla tube reaches a length of 0.5 to 1 centimeter and has an approximately square cross-section. The four crown lobes reach lengths of around 0.3 centimeters and have an approximately 0.5 millimeter long, bent back appendage. The lobed stylus is hairy woolly in the lower third.
The capsule fruits are cup-shaped to top-shaped with a length of 0.4 to 0.7 centimeters and a thickness of 0.3 to 0.4 centimeters. The endocarp is very lignified. Each of the fruits contains several dark brown seeds. They are irregularly shaped and compressed.
Occurrence and endangerment
The natural range of Kadua coriacea is on some islands belonging to Hawaii . Kadua coriacea was originally an endemic that was found on the islands of Hawaii , Maui and Oʻahu , but is now considered extinct on Maui and Oʻahu.
Kadua coriacea thrives at least on the island of Hawaii at altitudes of around 305 meters. The species grows there in dry to moderately moist forests.
Kadua coriacea is classified as Critically Endangered on the IUCN Red List . Displacement by invasive species as well as habitat destruction by imported and feral animals as well as droughts and forest fires are named as the main reasons for endangerment. The occurrences on Maui and Oahu are already considered extinct. The total stock, which is composed of a population of 167 plants , is seen as declining.
Taxonomy
The first description as Hedyotis coriacea was in 1802 by James Edward Smith in The Cyclopaedia; or, universial dictionary of arts,… . Warren L. Wagner and David H. Lorence transferred the species as Kadua coriacea in Systematic Botany in the genus Kadua in 2005 .
Individual evidence
- ↑ a b c d e f Kadua coriacea. In: Flora of the Hawaiian Islands. www.botany.si.edu/pacificislandbiodiversity/hawaiianflora, accessed on January 6, 2017 (English).
- ↑ a b c Kadua coriacea in the endangered Red List species the IUCN 2016 Posted by: M. Keir, 2016. Retrieved on January 6, 2017th
- ^ Kadua coriacea at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed January 6, 2017.
