23 June 2009

Astrotricha latifolia (Broad leafed Star hair)

The name Astrotricha comes from Astro meaning star and tricha meaning hair - from the dense woolly star-shaped hairs covering the stems and underside of the leaves of this plant.

You can clearly see the dense mass of white hairs covering the leaf stalks, stems and branches of the shrub. The new leaf shoots and tiny new leaves are also covered in hairs.

Notice the long leaf stalks, (often as long as the leaf is wide). The length of the stalks is one of the major differences between A. latifolia and its close relative A. floccosa (Woolly Star-hair). This is a useful aid in identification when the shrubs are not in flower as there are many similarities between the shrubs.

Astrotricha latifolia is a mid to large shrub, 1 to 3 metres high, with lax spreading branches. Leaves are about 15 cm long and 2 – 8 cm wide, broadly oval to lanceolate in shape with a slightly drawn out tip, dark green above, sometimes glossy, and woolly beneath with a leaf stalk roughly 4 - 8 cm long. The leaves are held horizontally radiating around the woolly (floccose) stems. The leaves are heavily veined with an obvious indented mid vein and clearly defined lateral veins.

Flowers are typical of the Araliacae, individually tiny but clustered in branched umbels at the ends of stems.

Although each individual flower is small when grouped in large umbels on the ends of the branches they are very noticeable.

Each tiny flower consists of five strongly reflexed petals with 5 stamens attached to a disc which surmounts the ovary. They are yellowish green in colour.

Even the buds are covered in white hairs

They flower late spring to summer (October to January). Note the longicorn beetle visiting the flowers.

Astrotricha latifolia are an understory shrub of wet schlerophyll forest or rainforest margins along the east coast of Australia from about Bega in the south right up the Queensland coast. They are not fussy about soil types being found on shale, quartzite, sandstone, basalt and clay based soils.

Personal Observations

The leaves of Astrotricha latifolia are always chewed. At any time of the year you will find leaves with holes in them and generally an abundance of visiting insects, particularly spring and summer.

Note turned down leaf sheltering a caterpillar

It is not only the leaves that are popular, the flowers too have their share of visitors. Spiders lurk waiting for flying insects to visit and beetles fly in, from longicorns to little round ladybird like creatures.

Early in the flowering season a little iridescent green beetle visits.

Here a tiny yellow flower spider waits amongst chomped leaves for its dinner to fly in.

A robber fly is doing the same thing and there is another brown beetle top left corner.

I have noticed other plants with many insect visitors but this is one of the few which had sustained visits of many different insects for months on end.

One of my most exciting finds was to photograph a caterpillar on a leaf of Astrotricha latifolia. To my naked eye it looked like a bit of twig on the leaf as it is very tiny indeed, it would be lucky to make 10mm in length. It looked just like a tiny dark skinny elongated blob, not a caterpillar at all, but I had my suspicions.

Only blown up on the screen can you see that it is a caterpillar. I believe it belongs to Imbophorus aptalis
which I also photographed on the same shrub and flying nearby.

And my best photograph for last.

Imbophorus aptalis is very tiny, about 1-2 cm wing tip to wing tip. Photographing it was made easier by the fact that it kept quite still and allowed me to approach very closely. Perhaps it was willing itself invisible.

This little moth is so delicate and beautiful, with its feathery wings and tiny form, that were a little girl again I would think it a fairy and would spend my days searching for its fellows and my nights dreaming of their adventures.

My favourite book for attempting to name the plants on my 10 hectares of rainforest and dry schlerophyll forest is Native Plants of the Sydney District An Identification Guide by Alan Fairley and Philip Moore, published by Kangaroo Press and readily available. It is a great book because almost every plant has a photograph, particularly of the flowers, which is what I always notice first in any plant.

8 June 2009

Smilax australis family Smilacaceae

(commonly called Lawyer Vine, Barbed Wire Vine or Austral Sarsaparilla)
has an interesting article on Smilax in general. In Australia we have three Australian species of Smilax and five of Ripogonum and on the Central Coast of New South Wales we have two of each species.

If something long, thin and vine-like clutches at your clothes, arms or legs on a bush walk and won’t easily release you, chances are Smilax australis has grabbed your attention. It is a very common, tough, wiry climber that scrambles through dry rain forests and nearby shady gullies in the Australian bush; growing in all states in a wide variety of habitats. It has long tough stems, up to 8m or so, and the whole length of stem is covered in small, very sharp, prickles.

Those sharp thorns, with the aid of paired tendrils growing from the leaf nodes, enables S. australis to thread through bushes and scramble over shrubs and trees, sometimes making impenetrable thickets in the bush.

Thicket in flower

The leaves are simple, alternate, tough and leathery; broader at the base than the tip with a short tapering point, which can sometimes be shallowly notched, particularly when young. They are green on both surfaces with five prominent veins running the length of the leaf, and smaller veins radiating from those. Tiny superficial veins cover the surface of older leaves. They are somewhere between 5 and 10 cm long. The base of the leaves houses a pair of coiled tendrils which also aids in the climbing and clinging process.

New leaves are a lovely soft pink when they first appear, aging to a pretty soft green and maturing to a leathery dark green.

The plants are dioecious and so have male and female flowers on different plants. The plants are not self fertile and before fruit can set both male and female plants must be present. I have observed flowering occurring only in spring, with flowering lasting for just a few weeks, but other references describe it as occurring at any time of the year. The flowers are greenish white to cream, individually quite small and borne in umbels about 5 cm across, downward hanging on fine stalks. Each flower is broadly tubular with 6 spreading pointed reflexed lobes and in male flowers 6 long protruding stamens. Perfume is not noticeable to the human nose.

Staminate (male) flowers

Staminate (male) flowers

Female flowers lack the six protruding stamens but instead have an ovary awaiting fertilization before fruit can develop.

Pistillate (female) flowers

Pistillate (female) flowers

If the female flowers are fertilized a cluster of round green berries 5-8 mm across develops,

These ripen black and contain 1 or 2 seeds which are eaten by native birds, such as Satin bower bird and the Green cat bird, and then excreted and spread around the bush to grow new plants.

Butterflies are attracted to the flowers.

There is a very similar plant called Smilax glyciphylla which is not as robust, has narrower leaves, only three longitudinal veins and no prickles. Sometimes they occur in the same area, even growing together. The whole plant is much smaller; smaller leaves, smaller flowers and it is said to have sweet tasting berries and leaves which can be eaten when young and tender.