VicFlora Flora of Victoria

Multi-access key to the Cyperaceae of Victoria

Introduction

The multi-access key to the Cyperaceae of Victoria is a key to all 205 Cyperaceae (sedge) taxa that are known to occur in Victoria, both native and introduced. It contains 18 characters to help distinguish taxa from each other with, including place of occurrence, plant size, and several morphological features both vegetative and reproductive. It differs from the dichotomous keys provided in VicFlora by giving the user the flexibility to choose from one of the 18 characters provided rather than the user having to commit to investigate the particular features being questioned in the dichotomous keys. This has the benefit of:

  1. avoiding having to answer questions relating to a feature that may not be present in the sample when being identified,

  2. potentially being able to identify a taxon without needing to comprehend the most technical terminology and

  3. allowing the rapid identification of taxa with distinct features rarely encountered in the family

To use the key the user selects a feature from the features in the top left Features Available panel and clicks on the state present in their specimen to be identified. Once selected this feature and state will show as being selected in the Features Chosen panel directly below the Features Available panel. To undo a selection, click on the box next to the state chosen in the Features Chosen panel to erase the tick in the box. Once a feature state is chosen all the taxa that do not possess the chosen feature state are discarded in the bottom right Entities Discarded panel and those that do possess the chosen feature state are retained in the top right Entities Remaining panel. The user continues to choose further character states present in their specimen until identification is achieved. To restart the key when finished select the restart key icon represented by the two green arrows in the top left corner of the screen.

Go to Key Player

General helpful hints

For the most effective use of this key the user is encouraged to read the help guides for each character and state before submitting an answer for that character and state. Help guides and photographs can be found by clicking on the page icons beside characters and states. This help will reduce the chance of misinterpretation of the character and state. Some information and definitions required for interpreting a state may be given under character so users are encouraged to read the help guide for the characters before the states. When taking measurements or assessing which state a character exists in for the taxon being identified a typical plant and plant part should be used. Typical is here interpreted as a close representation of the average plant in terms of size and stature in a population and a plant part that represents the average condition for that character (e.g. average length, the most frequently observed shape etc.). The characters provided concern the adult plant and consequently when using these characters the plant chosen should be reproductively mature. For some of the characters it is possible for some taxa to possess more than one character state for the character. In such cases either correct character state can be chosen. When taking measurements be precise e.g. if a nut is 2.9 mm long enter 2.9 mm long rather than rounding up to 3 mm and entering that.

To help identify the specimen to be identified as quickly as possible the best option can be used. This option highlights which characters should be used first to discard the maximum number of taxa among the remaining taxa. To use the best option select the best icon given as a blue wand at the top of the screen. For some similar taxa such as closely related species or subspecies within a species it may become time consuming to keep using the key until one taxon remains. In such instances the user can use the dichotomous key and profiles to help distinguish between the remaining similar species.

Occurrence

One character that refers to where a plant can be found.

Natural Region

Victoria has been divided into 16 natural regions. For this character the user determines which natural region the plant that is to be identified was found in to enter for this character. Whether a taxon is regarded as occurring in a particular natural region or not is dependent on whether the taxon has been previously documented as occurring in that natural region or not. There is a remote possible that a taxon occurs in a natural region but has not yet been documented in that natural region. In such a case the key will not recognise that taxon as occurring in that natural region which will result in a misidentification for the user. This issue may be particularly relevant to newly introduced species which may be still expanding their range through Victoria or for taxa that are not collected often. Due to these issues we suggest that this character be one of the first characters investigated as a potential reason for misidentification.

Culm

A set of four characters that refer to the main stem that bears the inflorescence (flower mass) and any leaves.

Height cm

The height in cm from the base of the plant to the bract at the base of the inflorescence.

Diameter mm

The width of the culm at its widest point.

Cross-section

The shape left in the culm when looking down on a horizontal cut through the culm.

  • Trigonous or triquetrous

    In this state a triangular shape is left in the culm when looking down on a horizontal cut through the culm.

  • Terete

    In this state a circular shape is left in the culm when looking down on a horizontal cut through the culm.

  • Flat

    In this state the culm is flat without much internal cavity.

  • Biconvex, narrow-ellipsoid or with one side convex

    In this state an oval shape is left in the culm when looking down on a horizontal cut through the culm. Sometimes one side can be convex but the other is more or less flat.

  • Square

    In this state there are four angles in the culm and a square-like shape is left in the culm when looking down on a horizontal cut through the culm.

Nodes

This character refers to whether there are joints or swellings along the culm.

  • Present

    In this state the culm appears to be jointed or have swellings.

  • Absent

    In this state the culm is not interrupted by joints or swellings.

Inflorescence

A set of six characters that refer to the collection of flowers (inflorescence). The inflorescence is produced at the top of the culm. The flowers have a leaf or scale-like bract (glume), reproductive organs and often additional scales or bristles at the base of the ovary. Flowers are not colourful and showy as the stereotypical image of a flower portrays.

Length cm

The length in cm from the culm to the apex of the furthest flower from the culm. This measurement does not include the bract at the base of the inflorescence.

Type

This character refers to the form of the inflorescence.

  • Paniculate

    In this state flowers are grouped in basic units (spikelets) and there are several stalked spikelets that are arranged along a central main axis or along axes that join up with a main axis.

  • Anthelate

    In this state flowers are grouped in basic units (spikelets) and these form clusters some of which are borne on stalks that arise from the top of the culm.

  • Single spikelet or spike

    In this state flowers are grouped in a single unit (spikelet) or there are more than one spikelet attached directly to a main axis without stalks.

  • Lateral head

    In this state flowers are grouped in basic units (spikelets) and these form a tight cluster that arises on the side of a culm, near the top of the culm.

  • Terminal head

    In this state flowers are grouped in basic units (spikelets) and these form a tight cluster that arises at the tip of the culm.

Basic inflorescence unit length mm

The length of the basic unit that flowers are grouped into. In the majority of species this is a spikelet, in Carex it is a spike. For species that have only a single spikelet forming the inflorescence, the inflorescence length is the same as the basic inflorescence unit length.

Flower number per basic inflorescence unit

This is the number of flowers in a spikelet or spike. Glumes (the minute leaf-like scale protecting the flowers) without reproductive organs are excluded from this number.

Glume arrangement

This character refers to how the glumes (the minute leaf-like scale protecting the flowers) are positioned along the central axis of the basic inflorescence unit (spikelet of spike).

  • Distichous

    In this state the glumes are arranged in two rows, one row on one side of the central axis of the spikelet and the other along the opposite side of the central axis.

  • Spirally arranged

    In this state the glumes are not restricted to two distinct lines along the basic inflorescence unit.

Floret sexuality

This character refers to the sex of the flowers (florets) within an inflorescence.

  • Both unisexual and bisexual florets present

    In this state some of the flowers (florets) of an inflorescence are female without stamens or with infertile stamens (staminodes) or are with only fertile stamens or are functionally male because the female organs (pistillodes) are infertile.

  • All florets bisexual

    In this state all of the flowers (florets) of an inflorescence have both fertile male stamens and female styles and ovary.

  • All florets unisexual

    In this state all flowers (florets) in an inflorescence are either female or male.

Flower

A set of five characters that refer to the structures bearing the reproductive organs (flowers) that are often referred to as florets. The flowers have a leaf or scale-like bract (glume), reproductive organs and often additional scales or bristles at the base of the ovary. Flowers are minute and are not colourful and showy as the stereotypical image of a flower portrays.

Glume length mm

The length in mm of the minute leaf-like scale protecting the flowers. In Carex, this is often referred to as the bract.

Style arm number

This is the number of arms that the style or elongated female part of the flower that emerges from the top of the ovary divides into near its apex.

Stamen number

This is the number of male parts of the flower. The stamen comprises an anther which is typically an elongated oblong structure that is often yellow or white and is attached to the flower by a much more slender filament. Young flowers are best to use to address this character as stamens detach in older flowers.

Structures attached at base of ovary or nut

This character refers to whether there are structures other than the stamens and the glumes present at the base of an ovary or the nut (fruit).

  • Bristles

    In this state there are hair-like structures at the base of the ovary or nut that have minute barbs along their lengths.

  • Scales

    In this state there are flattened structures, often triangular or ovate, at the base of the ovary or nut.

  • Both scales and bristles absent

    In this state there are no structures other than the stamens, ovary and style under a glume.

Number of scales or bristles attached at base of ovary or nut

The number of structures, either scales or bristles, attached at the base of an ovary or nut (fruit).

Fruit

The product of the fertilized ovary in Cyperaceae is a nut or in Carex the nut is enclosed within a bottle-shaped bract, the whole structure referred to as a utricle. The following two characters refer to these structures.

Colour

The colour of the outside of the nut or utricle.

Length mm

The length in mm from the base of the nut or utricle to its tip.