Goodeniaceae

Goodeniaceae.

There are around 12 (10 to 17) genera with about 380 (300 to 440) species.
Over 90% of species are endemic to Australia with Scaevola being the exception.

Most are prostrate or sub-shrubs, sometimes scramblers and rarely trees.
Herbs can be up to 50 cm high and 1.5 m wide while sub-shrubs are up to 2 or 3 m high.
The simple leaves are almost always alternate and in a spiral.
They may be sessile or have a definite petiole but these are under 1 cm long.
In some the blade tapers to a narrow base forming an indistinct petiole up to 10 cm long.

The blades can be up to 5 (10) cm long and 3.5 cm wide.
They can be lance-shaped, ovate, obovate, round, elliptic or nearly linear.
The blade edges can be smooth, toothed or lobed.
There are often small clumps of hairs, often stellate in the axils of the veins on one or both surfaces.
Various parts of the plant have simple or glandular hairs. With the later the plants may be sticky.
Some species sucker easily.

Axillary or terminal inflorescences can be a single flower or a variously arranged cluster.
Even with single flowers they can so profuse they almost cover the leaves.
There are often bractioles under the flowers.
The bisexual flowers are almost allways zygomorphic (bilaterally symmetric).

There are 5 (3) mostly small sepals that may be free or have their bases fused.

The fused bases of the 5 petals form a long or short corolla tube that is almost always split in 1 or 2 areas.
The lobes may form 2 lips (bilabiate) or all 5 lobes may be on one lip (fan-shaped).
The lobes may be similar or of different sizes.
The tips of the lobes may be incised and there may be glandular hairs at the base.

The petals have a distinct central guide for pollinators that differs in texture and colour from the rest of the petal.
The thinner sides of the petals are commonly described as wings and their prominence varies or they may be absent.

There are often some petals with small appendages or auricles below the wings that surround the stamens.
Some species have a pouch or a spur.
Colours include blue, white, pink, mauve, yellow, orange or red.

The 5 stamens inserted at the base of the corolla tube alternate with the petals.
Usually the anthers either touch or are fused to each other forming a tube.
An exception is Scaevola where the stamens are free.
The anthers open inwards via longitudinal slits and in many species the pollen is shed before the flower opens.

The ovary is mostly inferior but can be partly inferior to superior.
Of 2 carpels it typically has 2 (1 or 4) locules each with 1 to many ovules with basal or axile placentation.
There is a single style with a stigma that may be bilobed.

Just below the stigma is a cup-like indusium that may have hairs on the margin and a beard at the base.
The upper edge may be flat or have a notch.
It is the defining feature of the Goodeniaceae.

In the bud the style is shorter than the stamens and the indusium collects the pollen shed into the anther tube.
When the flower opens the style elongates well past the stamens.
The enlarging stigma forces the pollen out of the pollen presenter (the indusium) and it adheres to pollinators.
When the pollen has all gone the stigma becomes receptive to pollen from another flower.

Some species have nectaries among the stamen bases.

The fruit are mostly capsules with a few drupes or nuts.
The calyx is often still attached.
The flat seeds from capsules often have wings.

Scaevola, often cultivars are fairly commonly seen in Australian gardens but Goodenias and Dampieras are only occasionally seen.

J.F.

Genus