Strelitzia family

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Strelitzia family
Bird of Paradise (Strelitzia reginae)

Bird of Paradise ( Strelitzia reginae )

Systematics
Subdivision : Seed plants (Spermatophytina)
Class : Bedecktsamer (Magnoliopsida)
Monocots
Commelinids
Order : Gingery (Zingiberales)
Family : Strelitzia family
Scientific name
Strelitziaceae
( K.Schum. ) Hutch.
Genera

The Strelitziaceae are a family of plants in the order of the ginger-like (Zingiberales). This family contains only three genera with seven species. Some species are used as ornamental plants .

Description and ecology

Appearance and leaves

They are perennial , herbaceous plants , some of which are very large. They form short branched rhizomes . The above-ground shoot axes are mostly unbranched or rarely branched dichotomously. Many plants are often clumped together. An exception within the order of the Zingiberales are the woody shoot axes in Phenakospermum and Ravenala . There is no secondary growth in thickness , which is why the “ travelers ' tree ” is botanically also referred to as a tree-shaped plant and not a tree.

The alternate and two-lined leaves are divided into leaf sheath, petiole and leaf blade. The long, simple leaf blades have a prominent midrib and almost parallel, but slightly sigmoid, so weakly S-shaped running side nerves that meet near the smooth leaf edge. As with the sister group of the banana plants (Musaceae) and as with the cane plants (Cannaceae), the leaves show convolute vernation (rolled buds). There are no ligules.

Inflorescences and flowers

Inflorescence of the bird of paradise flower ( Strelitzia reginae )
Blue hairy aril of seeds in cracked capsules of Ravenala madagascariensis

The lateral or terminal inflorescences (inflorescences) are winding and have boat-green bracts (bracts) that use to sit the pollinating birds.

The hermaphrodite flowers are zygomorphic and threefold. There are two circles, each with three bracts . The three free bracts of the outer circle are the same or different. Of the three bracts of the inner circle, the two lateral ones form an arrow-like envelope around the stylus, in Strelitzia also around the stamens. Originally there are two circles with three fertile stamens each. In Ravenala every six stamens are present, but for all other species are absent one of the inner circle. In contrast to many other families of the order, no stamens are converted to staminodes . The two-celled pollen grains have no aperture and they largely lack an exine, but they have a thick intine. Three carpels are one under constant ovary grown, with many (20 to 50) central angle constant ovules in each of the three chambers ovary; it has an extension that forms a solid tube. There are septal nectaries that have sunk deep into the ovary wall . The stylus ends in a simple or trilobed scar. Most species are pollinated by birds ( ornithophilia ), Phenakospermum by bats ( chiropterophilia ), Ravenala by lemurs .

Fruits and seeds

They form woody, loculicidal capsule fruits .

The seeds always have a starch- rich endosperm and always an aril. The conspicuous, brightly colored ( blue in Ravenala , orange in Strelitzia , red in Phenakospermum ) Arillus is slit lobed or intensely hairy. The seeds are mostly spread by birds.

Ingredients and sets of chromosomes

In the mesophyll are calcium oxalate crystals embedded as raphides. Starch is stored in the seeds and rhizomes.

The basic chromosome numbers are n = rarely 7 or 9, usually 11; For example, chromosome numbers of 2n = 14 or 2n = 22 were determined.

use

Few species are used as ornamental plants throughout the tropical belt .

Distribution map that shows the distribution area of ​​the genera only imprecisely, since the area is too small for Phenacospermum and too large for the other two genera

Systematics and distribution

The distribution areas are tropical South America (only Phenakospermum ), eastern South Africa (only Strelitzia ), Madeira and Madagascar (only Ravenala ).

First a subfamily Strelitzioideae was set up within the Musaceae in 1900 by Karl Moritz Schumann . It was placed in 1934 by John Hutchinson in The Families of Flowering Plants , Volume 2, p. 72 in the rank of a family of the Strelitziaceae. The type genus is Strelitzia Ait. The botanical genus name Strelitzia honors Princess Charlotte of Mecklenburg-Strelitz (1744-1818), the wife of the English King George III.

According to molecular biological studies, the Strelitziaceae are the sister family of the Lowiaceae and closely related to the families Heliconiaceae and Musaceae .

The family contains three genera, two of which are monotypical , with a total of seven species:

Habit and inflorescences of Strelitzia juncea
Strelitzia nicolai inflorescence
  • Strelitzia ( Strelitzia Ait. ): The five species are distributed along the eastern coast of South Africa:
  • Ravenala Adans. : It contains only one type:
    • Tree of the Travelers ( Ravenala madagascariensis Sonn. ): The original distribution area is in eastern Madagascar at altitudes below 1000 meters. It is planted as an ornamental plant in parks throughout the tropics. It grows very large and forms a trunk.
  • Phenacospermum Endl. : It contains only one species. A second species is reported: Phenakospermum amazonicum (Mart.) Miq. , it was even placed in its own genus Musidendron Nikai . Today this is only considered a synonym of Phenakospermum guyannense :
    • Phenakospermum guyannense (LCRich.) Endl. ex Miq. : It iswidespreadin the entire Amazon basin , in tropical northern and central South America east of the Andes . It reaches heights of 2 to 5 meters and looks similar to the "tree of travelers", but has only a pseudo trunk similar to that of the bananas .

More pictures

Traveler's Tree ( Ravenala madagascariensis ):

  • inflorescence

  • Fruit cluster

swell

Web links

Commons : Strelitziaceae  - Collection of images, videos and audio files