Wiliwili
| Wiliwili | ||||||||||||
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Wiliwili ( Erythrina sandwicensis ) |
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| Erythrina sandwicensis | ||||||||||||
| O.Deg. |
The Wiliwili ( Erythrina sandwicensis ) is a tree species endemic to Hawaii from the genus of the coral trees ( Erythrina ) within the subfamily of the butterflies (Faboideae). The species is characterized by a unique, gnarled shape and can survive on the almost bare and very dry lava fields. The wiliwili is in danger of disappearing as it could be displaced by the mesquite tree Prosopis pallida .
description
The Wiliwili reaches a height of 6 to 10 meters and a trunk diameter of 50 to 60 centimeters. The maximum values given are a height of 16.8 meters and a trunk diameter ( BHD ) of 1.2 meters. The trunk is usually short and thick and often crooked, the crown is expansive with strong and gnarled branches. The branches are almost horizontal and have yellow hairy tips. They show large leaf scars . The bark is yellow-brown to red-brown in color and occasionally covered with black or gray spines up to one centimeter long . The inner bark layer is light yellow.
The number of chromosomes is 2n = 42.
leaves
The tree shows the three-part, imparipinnate leaves typical of coral trees . They have a 9 to 25 centimeter long stem and are arranged alternately. The leaflets are 4 to 10 inches long and 6 to 15 inches wide. They are short-stalked and broadly triangular in shape with a horizontal base. The terminal leaflet is the largest. The upper side of the leaf is bald, the underside is hairy yellow and has clearly visible leaf veins . At the base of each leaflet there are two point-shaped glands, one or two more are at the base of the leaf.
The wiliwili loses its leaves in late summer or autumn. The new shoots take place in the spring after the tree has flowered.
blossoms
The mostly yellow or orange colored flowers grow densely packed in inflorescences about 15 centimeters long . The flower color can differ from tree to tree. The single flowers have short stalks, the calyx is hairy yellow, jug-shaped, open on one side and about 15 millimeters long. The corolla is yellow, salmon or orange and consists of a 4 centimeter long flag and four other, much smaller petals (wings or boats). Ten about 3 centimeters long, curved, yellow or orange-colored stamens are formed, nine of which have grown together on the stamens. The stamp has a slender pen and a pedicled, narrow and hairy ovary .
fruit
Hard-skinned and dark brown legumes are formed as fruits that are 10 centimeters long and 13 millimeters wide . They are pointed at the ends and open when ripe. They contain between one and five, usually two bean-shaped and shiny orange-red, 13 to 15 millimeters large seeds.
germination
The germination takes place epigeal. After germination, 6 centimeters large, heart-shaped primary leaves form. After six to eight weeks, the seedlings are 20 to 30 centimeters high and have the three-part pinnate leaves typical of coral trees.
Chromosome number
The number of chromosomes is 2n = 42.
Distribution and location requirements
The Wiliwili was very common on the leeward sides of all the larger islands of the archipelago ( Niʻihau , Kauaʻi , Oʻahu , Molokaʻi , Lānaʻi , Maui , Kahoʻolawe , Hawaiʻi ) at altitudes between 150 and 600 meters. In the meantime, only a few locations have remained that are on weathered lava fields in the rain shadow of the mountain ranges with annual rainfall of around 500 millimeters. Under these conditions only the introduced species Prosopis pallida thrives in Hawaii .
Systematics
The Wiliwili is a species in the genus of coral trees. It used to be combined with the species Erythrina tahitensis, which only occurs in Tahiti, into one species.
use
The Wiliwili is not subject to any commercial use. The wood is very soft and difficult to work with. It has the lowest density of all tree species in Hawaii and was previously used by the population for outriggers on canoes and as floats on fishing nets. The orange-red seeds are used in traditional Hawaiian wreaths ( lei ). The wreath with which James Cook was greeted also contained such seeds.
swell
literature
- Schütt, Weisgerber, Schuck, Lang, Stimm, Roloff: Trees of the tropics . Nikol, Hamburg 2006, ISBN 3-933203-79-1 , p. 309-312 .
Individual evidence
- ↑ a b c Schütt et al .: Trees of the tropics . P. 310
- ↑ a b Erythrina sandwicensis O. Deg. In: Flora of the Hawaiian Islands. Smithsonian Institution, accessed February 20, 2009 .
- ↑ a b c d e Schütt et al .: Trees of the tropics . P. 311
- ↑ Erythrina sandwicensis at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis
Web links
- Erythrina sandwicensis. In: Hawaiian Native Plant Propagation Database. College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa, accessed February 20, 2009 .
- Forest & Kim Starr: Erythrina sandwicensis. In: Plants of Hawaii. Hawaiian Ecosystem at Risk Project (HEAR), accessed February 20, 2009 (English, with many photos).