Under Construction

Danaea

Maarten Christenhusz
Click on an image to view larger version & data in a new window
Click on an image to view larger version & data in a new window
taxon links [up-->] [up-->] [up-->] [down<--]Marattiaceae Interpreting the tree
close box

This tree diagram shows the relationships between several groups of organisms.

The root of the current tree connects the organisms featured in this tree to their containing group and the rest of the Tree of Life. The basal branching point in the tree represents the ancestor of the other groups in the tree. This ancestor diversified over time into several descendent subgroups, which are represented as internal nodes and terminal taxa to the right.

example of a tree diagram

You can click on the root to travel down the Tree of Life all the way to the root of all Life, and you can click on the names of descendent subgroups to travel up the Tree of Life all the way to individual species.

For more information on ToL tree formatting, please see Interpreting the Tree or Classification. To learn more about phylogenetic trees, please visit our Phylogenetic Biology pages.

close box
This tree is based on Christenhusz et al. (2008)
Containing group: Marattiaceae

Introduction

The genus Danaea is one of the few genera of ferns that are exclusively Neotropical. It can be found from Mexico, through all of Central and South America, south to Bolivia, Paraguay and Southeast Brazil. It also occurs on all the Greater Antilles, the more humid Lesser Antilles and on Cocos Island (Christenhusz 2007).

Danaea consists of approximately 50 species and occurs mainly in permanently wet forests on well drained soils. Several species seem to prefer steep slopes or creek banks in mostly undisturbed rainforests, although some species tolerate a moderate amount of disturbance. It  can be found in lowland rainforests, wet mountain forests and cloud forests, up to an elevation of 2650 m, but the genus is most diverse between 100 and 1000 m (Christenhusz 2007).

A study on growth rates in ferns has shown that the leaves of some Danaea species are very long-lived, and this makes the genus one of the slowest growing ferns with a long life expectancy (Sharpe 1993).

The generic name commemorates G. P. M. Dana (1736 - 1801) an Italian professor of botany.

Characteristics

Danaea can be recognized by its dimorphic fronds, the fertile being more contracted than the sterile. The synangia are fused and sunken into the lamina, in a row between the veins, generally covering most of the lower surface of the lamina.

The mature fronds are mostly once pinnate but simple (in D. carillensis and D. simplicifolia) and bipinnate (in D. bipinnata and sometimes in D. nodosa and D. urbanii). The terminal pinna can be present or replaced by a prolific bud, which can grow out into a new plant and can contribute substantially to the reproduction of a species. Between the pinnae there are usually swollen nodes, which in many species continues on the stipe, in the form of swollen articulations without pinnae. The venation is free, simple, paired at base or once branched.

The rhizomes are erect or creeping. The creeping ones can be dorsiventrally or radially arranged, the erect ones are radially arranged and held upright by numerous proproots.

Discussion of Phylogenetic Relationships

In several studies Danaea was found to be the basal lineage in the extant Marattiaceae. (Christenhusz et al., 2008; Murdock, 2008). Sometimes the genus was therefore placed into its own family the Danaeaceae, but morphological characters of vascular structure and a eusporangiate synangium clearly places this genus within the Marattiaceae.

The molecular phylogenetics of Danaea have only recently been studied on the basis of three plastid regions (Christenhusz et al, 2008). Based on morphological characters the genus can be divided into three groups (Christenhusz & Tuomisto, 2005), which agrees with the three groups found in the molecular studies (Christenhusz et al., 2008). The three groups are (after Christenhusz, 2007; naming of groups follows Presl, 1845):

"Danaea" and "Holodanaea" are most closely related; "Arthrodanaea" is sister to these.

References

Christenhusz, M. J. M. (2007). Evolutionary History and Taxnomy of Neotropical Marattioid Ferns: Studies of an ancient lineage of plants. Annales Universitatis Turkuensis ser. AII, tom. 216, pp. 1-134.

Christenhusz, M. J. M. and Tuomisto, H. (2005). Some notes on the taxonomy, biogeography and ecology of Danaea (Marattiaceae). Fern Gaz. 17, pp. 217-222.

Christenhusz, M. J. M., Tuomisto, H., Metzgar, J. S. and Pryer, K. M. (2008). Evolutionary relationships within the neotropical, eusporangiate fern genus Danaea (Marattiaceae). Molec. Phylog. Evol. 46, pp. 34-48.

Murdock, A. (2008). A taxonomic revision of the eusporangiate fern family Marattiaceae, with description of a new genus Ptisana. Taxon 57, 737-755.

Presl, C. B. (1845). Marattiaceae. In: Genera Filicacearum, Supplementum Tentaminis Pteridographiae, pp. 7-40. Prague.

Rolleri, C. H. (2004). Revisión del género Danaea (Marattiaceae-Pteridophyta). Darwiniana 42, pp. 217-301.

Sharpe, J. M. (1993). Plant-growth and demography of the neotropical herbaceous fern Danaea wendlandii (Marattiaceae) in a Costa-Rican rain-forest. Biotropica 25, pp. 85-94.

Information on the Internet

Title Illustrations
Click on an image to view larger version & data in a new window
Click on an image to view larger version & data in a new window
Scientific Name Danaea antillensis Christenhusz
Location Dominica, Emerald Pool
Specimen Condition Live Specimen
Identified By Maarten Christenhusz
Life Cycle Stage sporophyte
Copyright © Maarten Christenhusz
About This Page

Maarten Christenhusz
The Natural History Museum, London, United Kingdom

Correspondence regarding this page should be directed to Maarten Christenhusz at

Page: Tree of Life Danaea. Authored by Maarten Christenhusz. The TEXT of this page is licensed under the Creative Commons Attribution-NonCommercial License - Version 3.0. Note that images and other media featured on this page are each governed by their own license, and they may or may not be available for reuse. Click on an image or a media link to access the media data window, which provides the relevant licensing information. For the general terms and conditions of ToL material reuse and redistribution, please see the Tree of Life Copyright Policies.

Citing this page:

Christenhusz, Maarten. 2009. Danaea. Version 23 January 2009 (under construction). http://tolweb.org/Danaea/56784/2009.01.23 in The Tree of Life Web Project, http://tolweb.org/

edit this page
close box

This page is a Tree of Life Branch Page.

Each ToL branch page provides a synopsis of the characteristics of a group of organisms representing a branch of the Tree of Life. The major distinction between a branch and a leaf of the Tree of Life is that each branch can be further subdivided into descendent branches, that is, subgroups representing distinct genetic lineages.

For a more detailed explanation of the different ToL page types, have a look at the Structure of the Tree of Life page.

close box

Danaea

Page Content

articles & notes

collections

people

Explore Other Groups

random page

  go to the Tree of Life home page
top