Fact sheets for gaining a better understanding of southern Australian algae.
What is it?
- This is a collection of images
of attached (benthic) marine algae from southern Australia, with summaries of their key features. Microscopic algae such as plant plankton
are not included.
- It’s intended to aid
students and marine enthusiasts in becoming more familiar with the rich
algal diversity of our southern Australian coasts. Many marine projects
to be successful require algal identification. These fact sheets can
provide useful aids to naming “that seaweed”.
What is included?
- Each species has a page of coloured
photos of whole plants and magnified views of important parts, generally
taken from herbarium sheets (pressed specimens).
- Another page has images of
microscope preparations and descriptions of important structures written with
a minimum of technical terms and provided in a standard format
- There are also pictured keys to systematically identify
some groups of algae, and pages that allow a quick visual comparison of
What is the background to the fact sheets?
- Through the personal
efforts of Emeritus Professor H B S Womersley, and those of his many
students and helpers, some 90,000 algal specimens have been amassed in the
main collection of the South Australia State Herbarium.
Added to this are 24,000 prepared microscope slides of
algal structures essential in species identification.
These fact sheets should allow information from this overwhelming
wealth of material to be more accessible
and usable for the public without compromising its accuracy or prime use
How is it designed?
Each folder holds a related group
(or taxon) of algae. The arrangement of major groups –algal Families– follows
that in Womersley, H B S, 1984-2003 The Marine Benthic Flora of southern Australia. Parts I, II, IIIA-IIID.
Genera and species within a single genus are mostly
placed in alphabetical order unless they are more easily identified by grouping
them according to their shape.
Where possible, commonplace
language has been used in order to reduce botanical terms.
What are the fact sheets for?
Fact sheets highlight the
important but often obscure characteristics of specimens that have to be found
before you can confidently and correctly name species.
Beware. They are not complete descriptions of the
species. Obscure reproductive criteria may be omitted. Complete descriptions
can be found in Womersley’s 6 volumes of the Marine Benthic Flora that must act
as the final and authoritative method of identification.
Fact Sheets will give you a good start
to identification, however.
How are the fact sheets arranged?
The number at the top right
designates a particular Phylum and Family (and occasionally for large Families,
a Tribe) and follows a similar scheme used throughout the herbarium to organise
Icons indicate what special techniques may be needed,
such as using hand lenses, sectioning and microscope work.
The “Features” section looks at
relatively superficial features that may aid in rapid identification of the
Then follows the “Special requirements” section,
listing key features often demanding more detailed
examination and skilled techniques.
Coloured images of whole plants and
close-ups are included. The Australian 10¢ piece alongside images is provided as a
familiar scale. It is 24mm or almost 1" across.
Microscope images showing key
characteristics are found in “Details of anatomy”.
What are the numbers found alongside images?
Numbers starting with “A” refer to
pressed specimens in the algal section of the Adelaide herbarium.
Other numbers refer to prepared microscope slides.
Why are images different in colour?
Blue images indicate the specimen has been stained with
aniline blue to enhance the cell contents.
Images with black backgrounds are made with dark-field microscopy,
which highlights surface and edge features.
Images with dull grey, greenish or pinkish backgrounds
and bright margins are made with
phase contrast or interference microscopy, which
enhances colourless features such as cell walls, plastids and hairs.
You must have the specimen you
intend identifying— the voucher specimen— in front of you when making an
identification. It can be pressed already, but preferably a fresh or preserved
sample bearing reproductive parts should also be used. You may need to dissect or
view this under microscopes to get a correct identification. The State
Herbarium has some facilities for this. Seek help if this is necessary as some
of the techniques required can be difficult.
To identify a major group or
taxon, some simple pictured keys are provided. Then
it’s a matter of comparing the specimen you have with the
critical features in the fact sheet.
Ultimately you will need to
compare the features of your specimen with a full description in an authoritative
Marine Benthic Flora to be certain of a correct identification.