Gymnostoma

Gymnostoma chamaecyparis

The Gymnostoma ( Syn: Quadrangula ) are a genus of flowering plants in the family of Kasuarinengewächse ( Casuarinaceae ) from the order of book -like ( fagales ).

Description

All Gymnostoma species are evergreen woody plants: trees or large shrubs. Photosynthesis was mainly transferred to the branches, the leaves are greatly reduced. Your rods -like branches remind horsetails. The stomata are exposed on the branches. The leaves are borne in whorls about four. The leaf margins are smooth. Stipules absent.

Gymnostoma species are monoecious ( monoecious ) or dioecious ( dioecious ) getrenntgeschlechtig. Pollination is accomplished by the wind. The male are in pure, simple or compound acting aged men inflorescences. The female, pin- like inflorescences are on long or short side branches, whose appearance differs little from the vegativen branches.

Of the other genera of the family, it differs mainly by the broad bracts of the cone- shaped seed heads that are lignified between the bract pair. The fruits are dry, yellow - brown or grayish wing nuts (Samara ). The fruits of adjacent flowers form one fruit stand, part of which fruits are not fused into a fruit dressing.

Systematics and distribution

This genus was of L.A.S. Johnson ( Telopea 2: 83) in 1980 of the genus Casuarina ( Casuarina ) outsourced. The genus name is derived from the Greek words " gymnos " for naked and " stoma " for mouth, and refers to the exposed stomata on the branches.

One type ( Gymnostoma australianum ) is in northeastern Queensland / Australia, the rest are on the Malay Archipelago, the Solomon Islands, Fiji and eight species are native to New Caledonia.

Types (selection)

There are 16 to 18 Gymnostoma types:

• Gymnostoma australianum LASJohnson ( " Daintree pine" )
• Gymnostoma chamaecyparis
• Gymnostoma deplancheanum ( Miq. ) L.A.S.Johnson
• Gymnostoma glaucescens
• Gymnostoma intermedium
• Gymnostoma leucodon
• Gymnostoma mesostrobilum
• Gymnostoma nobile
• Gymnostoma nodiflorum ( Thunb. ) L.A.S.Johnson
• Gymnostoma papuanum ( S.Moore ) L.A.S.Johnson
• Gymnostoma poissonianum
• Gymnostoma rumphianum ( Miq. ) L.A.S.Johnson
• Gymnostoma sumatranum ( Jungh. ex de Vriese ) LASJohnson
• Gymnostoma webbianum

Swell

• K. L. Wilson & L.A.S. Johnson: Gymnostoma in Flora of Australia Online.
• Taxonomy.
• (Dissemination )
• Entry in GRIN.

Further Reading

• E. Navarro, T. Jaffre & P. Normand: Distribution and Phylogeny of Gymnostoma spp. Infective Frankia Strains in New Caledonia in Nitrogen Fixation: From Molecules to Crop Productivity, Springer Netherlands, pp. 459-460, doi: 10.1007/0-306-47615-0_256: Preview Online.