View source for Aa (plant)

{{Taxobox
| color = lightgreen
| name = ''Aa''
| regnum = [[Plant]]ae
| divisio = [[Flowering plant|Magnoliophyta]]
| classis = [[Monocotyledon|Liliopsida]]
| ordo = [[Asparagales]]
| familia = [[Orchidaceae]]
| subfamilia = [[Orchidoideae]]
| tribus = [[Cranichideae]]
| subtribus = [[Prescottiinae]]
| genus = '''''Aa'''''
| genus_authority = [[Heinrich Gustav Reichenbach|Rchb.f.]], 1854
| subdivision_ranks = Species
| subdivision = 
See text
}}

'''''Aa''''' Rchb.f. 1854, is a [[genus]] of plants belonging to the family [[Orchidaceae]]. The genus name apparently was rendered by the author to always appear first in alphabetical listings. Another - disputed - explanation, is that [[Heinrich Gustav Reichenbach]] named this genus after [[Pieter van der Aa]]; the printer of the Dutch botanist Paul Herman's "Paradisus Batavus"<ref>[http://falco.elte.hu/eoc/ParadisusBatavus.htm Paradisus batavus]</ref>.

Species in this genus can be found growing [[Soil|terrestrially]] in cold habitats near the snowline in the [[Andes]] and also in [[Costa Rica]]; they are usually found close to small streams. The elongated [[inflorescence]] grows from a basal rosette of [[Leaf|leaves]], terminating in a small white upside down [[flower]] with the lip at the top. This lip is fringed and hood-shaped. The flower gives off a pungent smell that attracts [[Fly|flies]]. This genus has often been confused with the orchid genus ''[[Altensteinia]]''.

== Species ==
*''Aa achalensis'' Schltr. [[1920]] (Argentina)
*''Aa argyrolepis'' Rchb.f. [[1854]] (Colombia to Ecuador)
*''Aa calceata'' (Rchb.f.) Schltr. [[1912]] (Peru to Bolivia) 
*''Aa colombiana'' Schltr. [[1920]] (Colombia to Ecuador)
*''Aa denticulata'' Schltr. [[1920]] (Colombia to Ecuador)
*''Aa erosa'' (Rchb.f.) Schltr. [[1912]] (Peru)
*''Aa fiebrigii'' (Schltr.) Schltr. [[1912]] (Bolivia)
*''Aa gymnandra'' (Rchb.f.) Schltr. [[1912]] (Bolivia)
*''Aa hartwegii'' Garay [[1978]] (Ecuador; Colombia; Venezuela)
*''Aa hieronymi'' ([[Cogn.]]) Schltr. [[1912]] (Argentina)
*''Aa inaequalis'' (Rchb.f.) Schltr. [[1912]] (Peru to Bolivia)
*''Aa leucantha'' (Rchb.f.) Schltr. [[1920]] (Colombia to Ecuador)
*''Aa lorentzii'' Schltr. [[1920]] (Argentina)
*''Aa macra'' Schltr. [[1921]] (Ecuador)
*''Aa maderoi'' Schltr. [[1920]] (Venezuela; Colombia; Ecuador)
*''Aa mandonii'' (Rchb.f.) Schltr. [[1912]] (Peru to Bolivia)
*''Aa matthewsii'' (Rchb.f.) Schltr. [[1912]] (Peru)
*''Aa microtidis'' Schltr. [[1922]] (Bolivia)
*''Aa nervosa'' (Kraenzl.) Schltr. [[1912]] (Chile)
*''Aa palacea'' (Kunth) Rchb.f. [[1854]] (Costa Rica to Bolivia)
*''Aa riobambae'' Schltr. [[1921]] (Ecuador)
*''Aa rosei'' Ames [[1922]] (Peru)
*''Aa schickendanzii'' Schltr. [[1920]] (Argentina)
*''Aa sphaeroglossa'' Schltr. [[1922]] (Bolivia)
*''Aa trilobulata'' Schltr. [[1922]] (Bolivia)
*''Aa weddeliana'' (Rchb.f.) Schltr. [[1912]] (Peru to NW Argentina)

== Reference ==
http://www.kew.org/wcsp/qsearch.do

==External links==
<references />
*[http://www.chilebosque.cl/herb/anervo.html Pictures of Chilean ''Aa nervosa'' orchid]

[[Category:Orchid genera]]
[[Category:Neotropical flora]]