Crossandra

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Crossandra
Crossandra nilotica

Crossandra nilotica

Systematics
Asterids
Euasterids I
Order : Mint family (Lamiales)
Family : Acanthus family (Acanthaceae)
Subfamily : Acanthoideae
Genre : Crossandra
Scientific name
Crossandra
Salisb.

Crossandra is a genus of plants from the Acanthus family (Acanthaceae). The 50 to 52 species are common in the Paleotropic .

description

Vegetative characteristics

Crossandra species usually grow as upright shrubs or perennial herbaceous plants . The plants are bare or hairy.

The opposite or in whorls arranged and stalked leaves are simple. The leaf margins are smooth to more or less notched. Stipules are missing.

Generative characteristics

End or lateral, often over a long inflorescence stem, are the spiked inflorescences in which the flowers are close together. The most eye-catching, relatively large, ovate-lanceolate, overlapping bracts in four rows arranged (they are often referred to as bracts) have a smooth edge; their arrangement gives the inflorescence a square appearance in many species. The hairy, linear-lanceolate bracts have at most about the same length as the sepals.

The often large, conspicuous hermaphrodite flowers are five-fold and zygomorphic with a double flower envelope . The five unequal sepals are only fused at their base. The top calyx lobe is the widest and has two nerves. The five petals are fused with narrow tubes. The narrow, curved corolla tube is longer than the corolla lip and ends with a single lip. The only crown lip is clearly unequal five-lobed. The color of the petals ranges from white or yellow to orange to red. There is a ring-shaped disc. The four fertile stamens usually do not protrude from the corolla tube. The stamens are shorter than the anthers. The fringed anthers have only one theca . Two carpels are an above-permanent, two-chambered ovary grown with two ovules per ovary chamber. The stylus, which becomes thicker towards the top, ends in a weakly bilobed scar.

The elongated, double-faced, more or less square capsule fruits contain four seeds . The ellipsoidal egg-shaped seeds have fringed scales or hairs.

ecology

The seeds are ejected explosively from the capsule fruit. The unit of spread ( diaspore ) is the seed.

Systematics and distribution

The genus Crossandra was established in 1805 by Richard Anthony Salisbury in The Paradisus Londinensis sub , plate 12. The botanical genus name Crossandra is derived from the Greek words krossoi for fringes and andrós for man and refers to the fringed anthers. Synonyms for Crossandra Salisb. are: Harrachia Jacq. , Pleuroblepharis Baill. , Polythrix Nees , Strobilacanthus Griseb.

The Crossandra species are common in the Paleotropic : There are species in Africa , Madagascar (about 25 species), on the Arabian Peninsula and the Indian subcontinent .

The genus Crossandra belongs to the tribe Acantheae in the subfamily Acanthoideae.


There are several varieties of the ornamental plant Crossandra infundibuliformis . Clearly visible: the square-shaped inflorescence and the single-lipped, orange-colored crown on a long stem.
Crossandra massaica
Crossandra mucronata
Crossandra puberula

Selected species

There are 50 to 52 accepted species in the genus Crossandra :

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Individual evidence

  1. ↑ a b c d e f g h i j k l Kamal Akhtar Malik, Abdul Ghafoor: Crossandra at Tropicos.org. In: Flora of Pakistan . Missouri Botanical Garden, St. Louis
  2. ↑ Crossandra at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed on 2017-12-2.
  3. ↑ a b Crossandra at Tropicos.org. In: Catalog of the Vascular Plants of Madagascar . Missouri Botanical Garden, St. Louis
  4. ^ A b c d Crossandra in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved December 24, 2017.
  5. ↑ a b c Crossandra at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis

Web links

Commons : Crossandra  - collection of images, videos and audio files