Spiraeanthemum
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Spiraeanthemum katakata , illustration |
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Spiraeanthemum is a plant kind from the family of Cunoniaceae . It occurs with 19 types of shrubs and trees on the northern Moluccas , in Melanesia , northeast Australia and on the Samoan Islands . Some authors separate a large part of the species into a separate genus Acsmithia Hoogland .
description
Vegetative characteristics
The Spiraeanthemum species are shrubs or small to medium-sized trees with evergreen foliage. The branches often have thickened nodes . The leaves are opposite or in three- to four-fold, sometimes five-fold whorls . The stipules are designed as "interpetiolar stipples". They are found at the nodes between the attachment points of the petioles , usually in the same number as these. They are undivided, triangular-ovoid to linear-lanceolate, usually fall off early and then leave behind elliptical to elongated, straight to curved scars. The simple and undivided, pinnate leaf blades are entire or notched-serrated. Along the midrib, rarely, along side nerves in the nerve angles often Acarodomatien present. These are either pit-like or pocket-like cavities or tufts of hair, but usually a combination of both. The indument consists of simple, single-celled hair . Between these, secretion glands are visible as red dots on the leaf surface and on the nerves .
Inflorescences
The inflorescences are floriferous panicles . They are usually single, sometimes also serially inserted in pairs in the leaf axils . In the Spiraeanthemum densiflorum group in particular , the inflorescences can sometimes - always in the case of Spiraeanthemum davidsonii - end up on the branches. Rarely comes Cauliflory ago. The length of the peduncle is in most species about 20–50 percent of the total length. In the Spiraeanthemum densiflorum group, however, the axillary panicles are usually sessile, ie they have an opposing pair of side branches directly at the base. The panicle branches are opposite at the lower nodes or arranged in three to four-fold whorls, at the upper nodes mostly less regular and ± alternating . Their bracts are small and decrepit. The flowers are on articulated flower stalks individually or in clusters on the last branches of the panicle. The flowers of a panicle all ripen at the same time.
blossoms
The small, white to yellowish or greenish flowers are either hermaphroditic or unisexual. In the latter case, the gender distribution is dioecious . The radial symmetry , (3–) 4–5 (–6) -folded flowers have a flat flower base . The inflorescence consists only of the somewhat leathery sepals, which are ragged in the bud and fused together at the base for ¼ – ½ of their length . Petals are missing. There are usually twice as many stamens as there are sepals. Their number is rarely irregular or sometimes it only corresponds to the number of calyx lobes. The stamens consist of awl, bare stamens and small anthers, which are movably attached to the stamen on their back (dorsifix). The broad, heart-shaped to transversely oval anthers are edged or incised at the tip, incised at the base and open lengthways. In female flowers the anthers are reduced to half the size and are probably sterile, rarely possibly fertile. The nectar disc consists of individual, bald or slightly hairy lobes, the number of which originally corresponds to the number of stamens. The disc lobes are either free and then alternate with the stamens, or they are sometimes - always in male flowers - fused together in pairs. In the latter case, the pairs are separated by the stamens standing in front of the sepals and are arranged against the center of the flower in front of the stamens that stand between the sepals. In male flowers, the discus lobes, which are fused in pairs, are pressed close together and enclose a cavity in the center of the flower. The gynoeceum is completely absent in male flowers . In female and hermaphrodite flowers there are 2–6 upper, ± free carpels , but often not all of them develop to fruit ripe. The egg-shaped, hairy carpels continue in a stalk-round, bald or only a few hairs at the base stylus . The small, terminal scar is club-shaped and covered with papillae . Each carpel contains 1–4 (–6) pendulous, winged ovules, which are narrowed at both ends, approximately in the middle or near the upper end .
Fruits and seeds
The calyx, the style and sometimes the stamens remain in the fruiting state. In each flower, 2–5 small, free follicles with the base only attached to the base of the flower develop from the carpels , which all open along the entire ventral seam. The stiff, leathery, boat-shaped fruit flaps have slightly thickened edges. Each individual follicle contains 1–4 elongated, glabrous, differently winged seeds .
distribution and habitat
The distribution area of the genus extends from the Moluccas Islands Halmahera and Bacan over New Guinea , the Bismarck Archipelago and the Solomon Islands to Vanuatu , Fiji and Samoa. New Caledonia has the greatest biodiversity with seven species. A single species, Spiraeanthemum davidsonii , occurs in eastern Queensland on the Australian continent. Most species have a small range and only occur on a single or a few relatively small islands.
The majority of the species of the genus Spiraeanthemum occurs in tropical rainforests of the low-lying and lower mountain ranges. Some species reach up into the cloud forests or occur in scrub forests on peaks and on exposed ridges , such as Spiraeanthemum pulleanum , which in New Guinea reaches an altitude of 2,650 m. The species occurring in New Caledonia also colonize relatively dry bush forests on serpentinite or grow in mesophilic forests, preferably on streams. The species occur mainly in the lower layer and the shrub layer of the forests, occasionally also on the edges of the forest and in secondary forests . Especially in low-growing, mossy mountain forests, the species also grow in the upper class.
Flower and fruit biology
The small, white to yellowish flowers arranged in easily visible inflorescences with a flat base and the presence of a nectar- producing disc indicate unspecialized pollinators such as short-nosed bees , wasps , flies , butterflies and beetles , as is the case with the other representatives of the Cunoniaceae . The winged seeds are spread by the wind.
Taxonomy and systematics
The genus Spiraeanthemum was described in 1854 by the American botanist Asa Gray on the basis of collections from the United States Exploring Expedition , first in a short report to the American Academy of Arts and Sciences and shortly afterwards again in more detail. The first description of the species involved two types samoense spiraeanthemum and vitiense spiraeanthemum , and took place at the Gray very far - including Cunoniaceae - combined Saxifragaceae (Saxifragaceae). The American botanist Albert C. Smith selected Spiraeanthemum samoense as a lectotype in 1952 .
In 1979 the Dutch botanist Ruurd Dirk Hoogland separated his own genus Acsmithia , named in honor of Albert C. Smith , which comprised species with lively foliage and hermaphrodite flowers. He limited Spiraeanthemum in the narrower sense to species with opposite leaf positions and unisexual, dioeciously distributed flowers.
In a molecular biological study on the basis of sequences of the chloroplast - DNA have spiraeanthemum and Acsmithia together as sister group shown all other representatives of Cunoniaceae. This could also be underpinned with morphological features. As a result, these two genera were combined in the tribe Spiraeanthemeae Engl . Only here do free carpels occur within the Cunoniaceae.
Another molecular biological study based on a region of the plastid - genome and two genes from the nucleus showed in 2009 that spiraeanthemum although in the strict sense monophyletic , but in the paraphyletic genus Acsmithia is embedded. As a consequence, the authors therefore suggested that Spiraeanthemum should be broadly defined, including Acsmithia . They were able to distinguish between two groups of species within Acsmithia , an Acsmithia densiflora group with 2–4 (–6) ovules in each carpel and hairy terminal buds and an Acsmithia brongniartiana group with only a single ovule and - with one exception - bare, often resinous Terminal buds. The phylogenetic relationships between Spiraeanthemum in the narrower sense and the two groups of species of Acsmithia are shown in the following cladogram :
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etymology
The name Spiraeanthemum is derived from Spiraea (Spierstrauch) and the ancient Greek word ἄνθεμον ( ánthemon , dt. Flower , blossom ). In the first description, Asa Gray emphasized the similarity in the flower structure with the rose family , especially the correspondence of the gynoeceum with that of the sparaceous bushes.
species
After expanding the genus to include the species previously assigned to Acsmithia , Spiraeanthemum now consists of 19 species. In New Caledonia, the investigation of the sequences of two genes from the nucleus has shown that there are cryptic species within Spiraeanthemum ellipticum and Spiraeanthemum pubescens . In both species, the morphologically indistinguishable populations of ultramafitite locations in the southern part of the island and of other substrates in the north each have genetic differences that correspond to those of independent species.
| Scientific name | distribution | Remarks |
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| Spiraeanthemum densiflorum group ( Acsmithia pp) | ||
| Spiraeanthemum davidsonii F. Muell. | Northeast Australia (Queensland) | |
| Spiraeanthemum densiflorum Brongn. & Gris | New Caledonia | |
| Spiraeanthemum integrifolium bottle | Moluccas, western New Guinea | |
| Spiraeanthemum parvifolium Schltr. | New Guinea | |
| Spiraeanthemum pulleanum Schltr. | New Guinea | |
| Spiraeanthemum reticulatum Schltr. | New Guinea, Louisiade Archipelago ( Misima ) | |
| Spiraeanthemum brongniartianum group ( Acsmithia pp) | ||
| Spiraeanthemum brongniartianum Schltr. | New Caledonia | |
| Spiraeanthemum collinum ( Hoogland ) Pillon | New Caledonia | |
| Spiraeanthemum ellipticum Vieill. ex pamp. | New Caledonia | Cryptospecies |
| Spiraeanthemum meridionale (Hoogland) Pillon | New Caledonia | |
| Spiraeanthemum pedunculatum Schltr. | New Caledonia | |
| Spiraeanthemum pubescens Pamp. | New Caledonia | Cryptospecies |
| Spiraeanthemum vitiense A. Gray | Fiji | |
| Spiraeanthemum ie p. | ||
| Spiraeanthemum bougainvillense Hoogland | Bougainville | |
| Spiraeanthemum graeffei Seem. | Fiji | |
| Spiraeanthemum katakata Seem. | Fiji | |
| Spiraeanthemum macgillivrayi Seem. | Bismarck Archipelago, Solomon Islands, Vanuatu | 2 subspecies |
| Spiraeanthemum samoense A. Gray | Samoa | |
| Spiraeanthemum serratum Gillespie | Fiji | |
gallery
use
For Spiraeanthemum parvifolium there is an indication that the bark of this species is used in folk medicine for stomach pain.
Danger
Only the four species found in the Fiji Islands are rated on the IUCN Red List of Endangered Species . According to this, Spiraeanthemum graeffei , Spiraeanthemum serratum and Spiraeanthemum vitiense (= Acsmithia vitiense ) are classified as "highly endangered" (EN) due to the few and small populations. Spiraeanthemum katakata is classified as “not endangered” (LC).
swell
- Bradford JC, Fortune Hopkins HC, Barnes RW 2004: Cunoniaceae. In: Kubitzki K. (Ed.): The families and genera of Vascular Plants. Vol. VI: Flowering Plants: Dicotyledons: Celastrales, Oxalidales, Rosales, Cornales, Ericales. Springer, Berlin / Heidelberg / New York, ISBN 3-540-06512-1 , pp. 91-111. - Preview in Google Book Search
- Fortune Hopkins HC, Hoogland RD 2002: Cunoniaceae . In: Flora Malesiana. Ser. I, Vol. 16. National Herbarium Nederland, Leiden, ISBN 90-71236-53-6 , pp. 53-165.
- Smith AC 1985: Family 117. Cunoniaceae. In: Flora Vitiensis Nova. A new flora of Fiji. Vol. 3. Pacific Tropical Botanical Garden, Lawai, Hawaii, pp. 5-26. - online
Individual evidence
- ↑ a b c d e f Pillon Y., Hopkins HCF, Munzinger J., Chase MW 2009: A Molecular and morphological survey of generic limits of Acsmithia and Spiraeanthemum (Cunoniaceae). Systematic Botany 34: 141-148. - doi : 10.1600 / 036364409787602410
- ^ Bradford JC, Fortune Hopkins HC, Barnes RW 2004 , p. 101. - Preview in Google book search
- ↑ Bradford JC, Fortune Hopkins HC, Barnes RW 2004 , p. 98. - Preview in Google book search
- ↑ Fortune Hopkins HC, Hoogland RD 2002 , p. 77.
- ↑ Dickison WC 1984: Fruits and seeds of the Cunoniaceae. Journal of the Arnold Arboretum 65: 149-190. - online
- ↑ Gray A. 1854a: Characters of new genera of plants, mostly from Polynesia, in the collection of the United States Exploring Expedition, under Captain Wilkes (continued). Proceedings of the American Academy of Arts and Sciences 3: 127-129. - p. 128 - online
- ↑ a b Gray A. 1854b: Ord.Saxifragaceae . In: United States Exploring Expedition. Vol. XV: Botany. Phanerogamia. Part IC Sherman, Philadelphia, pp. 663-688. - pp. 666-670 - online
- ^ Smith AC 1952: Studies of Pacific Island plants, XII. The Cunoniaceae of Fiji and Samoa. Journal of the Arnold Arboretum 33: 119-149. - p. 139 - online
- ^ Hoogland RD 1979: Studies in the Cunoniaceae. II. The genera Caldcluvia, Pullea, Acsmithia, and Spiraeanthemum. Blumea 25: 481-505. - see also: Acsmithia at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed April 23, 2013.
- ↑ Bradford JC, Barnes RW 2001: Phylogenetics and classification of Cunoniaceae (Oxalidales) using chloroplast DNA sequences and morphology. Systematic Botany 26: 354-385. - abstract
- ↑ Pillon Y., Hopkins HCF, Munzinger J., Amir H., Chase MW 2009: Cryptic species, gene recombination and hybridization in the genus Spiraeanthemum (Cunoniaceae) from New Caledonia. Botanical Journal of the Linnean Society 161: 137-152. - doi : 10.1111 / j.1095-8339.2009.00997.x
- ↑ Fortune Hopkins HC, Hoogland RD 2002 , p. 93.
- ↑ spiraeanthemum graeffei in the endangered Red List species the IUCN 2012. Posted by: World Conservation Monitoring Center, 1998. Accessed April 23, 2013.
- ↑ spiraeanthemum serratum in the endangered Red List species the IUCN 2012. Posted by: World Conservation Monitoring Center, 1998. Accessed April 23, 2013.
- ↑ Acsmithia vitiense in the Red List of Threatened Species of the IUCN 2012. Posted by: World Conservation Monitoring Center, 1998. Accessed April 23, 2013.
- ↑ spiraeanthemum katakata in the endangered Red List species the IUCN 2012. Posted by: World Conservation Monitoring Center, 1998. Accessed April 23, 2013.
Web links
- Spiraeanthemum in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved April 23, 2013.