Thick-leaf plants

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Thick-leaf plants
Magnificent stonecrop (Hylotelephium spectabile)

Magnificent stonecrop ( Hylotelephium spectabile )

Systematics
Subdivision : Seed plants (Spermatophytina)
Class : Bedecktsamer (Magnoliopsida)
Eudicotyledons
Nuclear eudicotyledons
Order : Saxifragales (Saxifragales)
Family : Thick-leaf plants
Scientific name
Crassulaceae
J.St.-Hil.
Illustration of Aeonium urbicum

The Crassulaceae (Crassulaceae) form a family that the order of the saxifrage-like part (Saxifragales). The plants of this family are able to store water in their thick leaves and thus to survive relatively unrivaled in dry places. They therefore belong to the leaf succulents and count to the CAM plants . Some species are used as ornamental plants , and the medicinal effects of some species have been studied.

description

Habit and leaves

They are mostly evergreen, one-, two-year and perennial herbaceous plants or woody plants either as half-shrubs or shrubs to grow. Most species are succulent plants with often fleshy stem axes .

The leaves are alternate, opposite or arranged in whorls, in basal rosettes or distributed along the stem axis. Usually the thick-fleshed leaves are simple. The leaf margins can be smooth, lobed or serrated. The stomata are mostly anisocytic. There are no stipules .

Inflorescences and flowers

The flowers are sometimes solitary or usually in terminal or lateral, zymose , paniculate , spike-like , racemose inflorescences together. The flowers are mostly hermaphroditic; In a few Rhodiola species, the flowers are rarely unisexual, then the species are dioecious, separate sexes ( dioecious ). There is a flower cup (hypanthium). The radial symmetry flowers are usually four to six-fold (three to 30-fold); So there are the same number of calyx, crown, carpels and stamens per stamen circle, mostly four to six (three to 30). The mostly long-lasting sepals are fused at most at their base. The petals can be free or partially fused to form a short tube. There are one or two circles with three to 30 stamens each. The two-celled pollen grains usually have three apertures and are mostly colporat. The upper or semi-lower carpels are not or slightly fused at the base. Per carpel there are seldom one to five, mostly up to fifty, pendulous, anatropic, bitegmic, crassinucellate or tenuinucellate ovules in submarginal placentation . There is a nectar scale on or near the carpels. The free stylus each end in a head-shaped scar. Pollination occurs by insects ( entomophilia ).

Fruits and seeds

The membranous or leathery follicles are free or fused at their base, upright or spread out and each contain one to many seeds. Some taxa are the follicles to collecting fruits (Synkarp) in Diamorpha even capsule-shaped fruit grown. The brownish, small, thread-like to ellipsoidal seeds contain at most a little oily endosperm and a straight embryo.

Ingredients and chromosome numbers

Often alkaloids ( pyrrolidine and piperidine alkaloids ) are present. Proanthocyanidins ( cyanidin and / or delphinidin ) or flavonols ( kaempferol , quercetin , myricetin ) or saponins may be present. Often tannins are present. Sedoheptulose is formed as a reserve substance .

The chromosome numbers are usually n = 4-22.

Systematics and distribution

Adromischus triflorus in its natural habitat: Small Karoo near Barrydale, Western Cape Province, South Africa

distribution

Thick-leaf plants can be found on all continents except in the Antarctic . Most species, however, occur in arid areas.

External system

Within the order of the Saxifragales, the Crassulaceae form a clade with the Aphanopetalaceae , Haloragaceae , Penthoraceae and Tetracarpaeaceae .

Internal system

The first publication of the family name was made in 1805 by Jean Henri Jaume Saint-Hilaire in exposure des Familles Naturelles , Volume 2, page 123. The type genus is Crassula L. . Synonyms of the family are Cotyledonaceae Martinov , Rhodiolaceae Martinov , Sedaceae Martinov , Sempervivaceae A.Juss. and Tillaeaceae Martinov .

Since succulent plants are difficult to dry, the appearance of herbarium and living plants can often vary greatly; this complicates the work with herbarium material and thus the delimitation of species and higher taxa. The taxonomy of the Crassulaceae was and is much discussed. Alwin Berger divided the family into six subfamilies in 1930, Henk 't Hart reduced these to two subfamilies in 1995. Recent phylogenetic investigations have led to a division of the family into three subfamilies and five tribe, which is as follows:

 Crassulaceae 

 Sempervivoideae 

Telephieae


   

Umbiliceae


   

Semperviveae


   

Aeonieae


   

Sedeae






   

Kalanchoideae



   

Crassuloideae



The Crassulaceae family consists of the following genera:

Tribus Umbiliceae: Phedimus kamtschaticus
Tribus Umbiliceae: Umbilicus rupestris
Tribus Umbiliceae: Rhodiola rosea
Tribus Umbiliceae: Phedimus kamtschaticus
Tribe Aeonieae: Aeonium simsii
Tribe Aeonieae: Aeonium valverdense
Tribe Sedeae: Echeveria elegans
Subfamily Crassuloideae: Crassula marnieriana

The systematic position of the genus Perrierosedum (A.Berger) H.Ohba is uncertain. It possibly connects the African Kalanchoideae with the Asian Telephieae. The previously independent genus Cremnophila Rose was integrated into the genus Sedum .

The following hybrid types also exist:

× Cremnosedum 'Little Gem'

use

From Rock navel herb ( Umbilicus rupestris ), the leaves can be eaten raw or cooked, the medical effect was investigated. The leaves of some Dudleya species can be eaten raw. At least the leaves of some Rhodiola species and sometimes other parts of the plant can be eaten raw and cooked. The medicinal effects of Orostachys japonica have been studied. Sedum species are used in a variety of ways: They serve as ornamental and aromatic plants, leaves can be eaten raw or cooked, and medicinal effects have been studied. Many species from several genera serve as ornamental plants for parks, gardens and spaces.

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literature

  • SB Gontcharova, AA Gontcharov: Molecular phylogeny and systematics of flowering plants of the family Crassulaceae DC . In: Molecular Biology . Volume 43, number 5, pp. 794-803, DOI: 10.1134 / S0026893309050112 .
  • Henk 't Hart, Urs Eggli: Evolution and Systematics of the Crassulaceae . Backhuis Publishers, Leiden 1995, ISBN 90-73348-46-3 .
  • Urs Eggli: Succulent lexicon Volume 4. Crassulaceae (thick-leaf plants) . 2003, ISBN 3-8001-3998-7 .
  • Pablo Carrillo-Reyes, Victoria Sosa, Mark E. Mort: Molecular phylogeny of the Acre clade (Crassulaceae): dealing with the lack of definitions for Echeveria and Sedum . In: Molecular Phylogenetics and Evolution . Volume 53, No. 1, 2009, pp. 267-276, DOI: 10.1016 / j.ympev.2009.05.022 .
  • J. Thiede, U. Eggli: Crassulaceae . In: Klaus Kubitzki (Ed.): The Families and Genera of Vascular Plants , Volume 9. Flowering Plants. Eudicots. Springer, Berlin / Heidelberg / New York 2007, ISBN 978-3-540-32214-6 , pp. 83-118, DOI: 10.1007 / 978-3-540-32219-1 12 .
  • David J. Mabberley: The Plant Book. A portable dictionary of the higher plants. Cambridge University Press, Cambridge et al. 1987, ISBN 0-521-34060-8 .

Individual evidence

  1. ↑ Armen Takhtajan: Flowering plants . 2nd edition, Springer, 2009, ISBN 978-1-4020-9608-2 , p. 305, DOI: 10.1007 / 978-1-4020-9609-9 .
  2. ^ J. Thiede, U. Eggli: Crassulaceae . 2007, p. 93.
  3. ^ J. Thiede, U. Eggli: Crassulaceae . 2007, pp. 100-113
  4. ↑ Crassulaceae . In: Urs Eggli: Succulents Lexicon Volume 4. Crassulaceae (thick-leaf plants) . 2003, p. 1
  5. ^ Umbilicus rupestris at Plants for a Future .
  6. ^ Dudleya at Plants for a Future .
  7. ^ Rhodiola at Plants for a Future .
  8. ^ Orostachys japonica at Plants for a Future .
  9. ^ Sedum at Plants for a Future .

Web links

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