Vanilloideae

Spice Vanilla ( Vanilla planifolia )

The Vanilloideae are a subfamily of the orchid family ( Orchidaceae). Mostly this group was made subfamily Epidendroideae, only recent studies, they confirmed as a separate subfamily. With about 200 species in 15 genera, it represents one of the smaller of the five subfamilies of this plant family

Features

All representatives of Vanilloideae are perennial, herbaceous plants, sometimes with slightly woody scion. The roots have velamen sometimes they form storage organs or specialize in mykoheterotrophe life; these species are mostly leafless. The leaves are spirally or sometimes arranged in two rows, the shoot is slender, sometimes extended liane -like. In the bud, the leaves are rolled and the leaf blade is leathery to fleshy. The Blattnervatur is sometimes reticulate, what can be observed extremely rare orchids. There is no separating tissue between leaf and shoot.

The inflorescences of Vanilloideae are terminal or pendant and unbranched. The flowers are spirally on the shoot, they are 'upside. The bloom is available in two threefold circles. The ovary is inferior and single chamber or dreikammerig. The only fertile stamen and the style are fused into a complex structure of the column. This is slender, the stigma simple, rarely are three stigma lobes to see. The stamen is the end of the column, and is aligned perpendicular to the latter. The pollen grains form a mealy, slightly sticky mass or are less likely to soft, formed contiguous pollinia. The fruits are mostly fruit capsules, sometimes fleshy. They contain numerous lens-shaped seeds, about one half to one millimeter in size and provided with a hard seed coat.

The chromosome numbers vary within the subfamily over a wide range of 2n = 18, 20 or 24 wherein the Pogonieae ( there are quite large, the chromosomes ) to be 2n = 28, 30 or 32 wherein the Vanilleae.

Dissemination

The types of Vanilloideae are found mainly in tropical America and Australasia, Vanilla has a pantropical distribution.

System

The subfamily is a sister taxon to a clade of the subfamilies Epidendroideae and Orchidoideae. You can in turn be divided into two tribes: the Pogonieae and Vanilleae. Dressler divides the Vanilleae further into the three subtribe Galeolinae, Lecanorchidinae and Vanillinae.

• Pogonieae Cleistes
• Duckeella
• Isotria
• Pogonia
• Pogoniopsis

• Galeolinae Cyrtosia
• Erythrorchis
• Galeola
• Pseudo Vanilla

• Lecanorchis

• Clematepistephium
• Dictyophyllaria
• Epistephium
• Eriaxis
• Vanilla

Documents

• Robert L. Dressler (1993 ): Phylogeny and Classification of the Orchid Family. Pp. 105ff. Cambridge University Press, ISBN 0-521-45058-6
• K. M. Cameron et al. (1999): A phylogenetic analysis of the Orchidaceae: evidence from rbcL nucleotide sequences. American Journal of Botany 86:208-224. Online, accessed on 17 October 2007