Hyophorbe

The last known specimen of Hyophorbe amaricaulis

Hyophorbe is an indigenous only to the Mascarene palm genus.

• 5.1 Notes and references

The representatives are single -stemmed, medium-sized palm with eye-catching crown stem and pinnate leaves. They are monoecious and repeatedly flowering. The trunk is significantly swollen in some species, in others of uniform diameter. The trunk is covered with annular leaf scars and gray.

The chromosome number is 2n = 32

The leaves are pinnate. Dead leaves fall off clean. The leaf sheaths form a distinct crown shaft. The petiole is short, strong and furrowed on the upper side, rounded at the bottom. The rachis is flat on the upper side and rounded at the bottom. The leaflets are folded lace up pointed, simple, stiff and have a clear midrib with up to two nerves on each side. On the underside of the midrib bears a distinct pubescence ( Ramenta ).

Inflorescences

The inflorescences are below the leaves ( infrafoliar ) and individually. You are branched three - to fourfold. In the bud stage they are horn-shaped and erect. Later, you will almost horizontal. The inflorescences are protandrisch. The cover page is very short, Roehrig, obsolete and opens at the top. The inflorescence axis is pronounced and somewhat longer than the peduncle. On Peduncle usually sit 5 (rarely 4-9 ) decrepit bracts. The first-order lateral branches are in a spiral arrangement, are upstanding and in the lower area free of branches. The flower-bearing axes ( Rachillae ) are slender, long and initially suspended and later stand-off. The bracts of side axes and Rachillae are no longer available to blossom.

Flowers

The flowers are flowering orange, yellow or white, and sometimes fragrant. They are available in rolls of a basal female and three to seven distal male flowers. Bracts of the winding and single flowers are not present at flowering time.

The male flowers are symmetrical or slightly asymmetrical in bud stage. The three sepals are free and imbricat, or fused at the base. The three petals are valvat and fused at the base. Six stamens have filaments that are fused to each other at the base, and are also connected to the crown and that extend beyond the tube. Distal to the filaments are free and upright. The anthers are dorsifix, the filaments start at or above the middle. Basal are the anthers half or more of their length in two parts ( bifid ), at the top only briefly bifid. The opening takes place latrors. The stamp rudiment is conical - ovate and shorter than the stamens. Sometimes it is also tiny and three-lobed. The pollen is ellipsoidal, asymmetric, while sometimes flat triangular. The germ is opening a distal sulcus, rarely a Trichotomosulcus. The longest axis measures 38-58 microns.

The female flowers are symmetrical and ovoid. The three sepals are free and imbricat, or fused basally into a cup; the sepals are then easily imbricat. The three petals are valvat or slightly imbricat, and fused at the base. The staminodes are fused at the base and form a sechszipfeligen cup. Sometimes they wear small, abortive anthers. The gynoecium is dreifächrig with one ovule. There are three to anthesis recurved, provided with minute papillae scars. The ovary has septal nectaries. The ovules put on the side of, and are hemianatrop have at Hyophorbe verschaffeltii an aril.

Fruit and seeds

The fruits are ellipsoid to globose or birnenförmib. They are orange to black, red or brown, and usually contain a seed. They carry scars basel radicals, also the perianth remains on the fruit and is then thickened. The exocarp is smooth or slightly rough or covered with tiny warts. The mesocarp is thin, fleshy, interspersed with numerous reddish tannin -containing cells as well as with several layers of flat fibers of different widths. The endocarp is thin. The seed is ovoid to ellipsoidal or spherical. The hilum is small, sits basal. The venation consists of a few simple or slightly branched strands emanating from the distal and lateral hilum. The endosperm is homogeneous. The embryo sits laterally to apical.

Dissemination and locations

Hyophorbe is endemic to the Mascarene Islands. Depending on a species occurs on Rodrigues and Réunion, three species in Mauritius and Round Iceland. The palm trees once covered the hills and valleys of the Mascarene Islands. Today, all species in the wild are almost extinct. They were probably palms of the forests up to 700 m above sea level, or perhaps the coast savannas ( Hyophorbe lagenicaulis ). The latter species is found only in a few individuals before on exposed rocks on round Iceland. The other species growing on volcanic soils or on volcanic and limestone soils ( Hyophorbe verschaffeltii ). From Hyophorbe amaricaulis there is only one copy in the Botanical Garden of Curepipe on Maritius, from the other four species there are only relatively few copies.

System

The genus Hyophorbe is placed in the subfamily Arecoideae, Tribe Chamaedoreeae within the family Arecaceae. The genus is monophyletic. The phylogenetic relationships of Hyophorbe within the tribe are not released.

In the World Checklist of Selected Plant Families of the Royal Botanic Gardens, Kew, the following types are recognized:

• Hyophorbe amaricaulis
• Hyophorbe indica
• Hyophorbe lagenicaulis
• Hyophorbe vaughanii
• Verschaffeltii Hyophorbe

The genus name is derived from the ancient Greek words for pig and feed, a reference to an earlier use of the fruit as pig feed.

Use

The species are used as ornamental plants and achieve commercially often high prices.

Documents

• John Dransfield, Natalie W. Uhl, Conny B. Asmussen, William J. Baker, Madeline M. Harley, Carl E. Lewis: Genera palmarum. The Evolution and Classification of Palms. Second edition, Royal Botanic Gardens, Kew 2008, ISBN 978-1-84246-182-2, pp. 370-372.