A Closer Look at a Fern

.....specifically, the Sori and Sporangia.

I spent some time photographing a fern today for the purpose of learning more about these pteridophytic plants. I particularly wanted to have a closer look at the little spore containing receptacles that are found on on the underside of fertile fronds.

Fronds of the Kangaroo Fern -  Microsorum pustulatum

The Kangaroo Fern, Microsorum pustulatum, in the above photo is growing on the trunk of a Tree Fern, Dicksonia antarctica. If you look closely at the enlarged photo you can see the rhizomes working their way through the fibrous trunk of the Tree Fern. On the upper surface of the fronds you can see little dimples marking the locations of the reproductive structures which are on the underside. These are the spore containing structures that I wanted to have a closer look at.

Turning the frond over we can see these raised spots arranged along the underside. These are known as sori, or in the singular, a sorus. On this specimen the sori are about 4mm in diameter. . So where are the actual spores? Let's look closer!

Each sorus is tightly packed with sporangia

This photo shows that the sorus is actually tightly packed with little capsules known as sporangia (singular, sporangium). Notice that the sporangia are open to the air. In some ferns there is a little cap that covers them until they are mature. The cap is known as an indusium. The presence or absence of an idusium can be a useful feature in identifying ferns. Another useful feature for identifying ferns is the shape and position of the sori.

Closer view of the sporangia

Getting up close you can see that each sporangium is a little capsule. These capsules open when mature. The microscopic spores are then released to be spread by the wind.

Ferns Along Seabrook Creek

...at the Frenchs Road Nature Reserve.

Anyone interested in ferns would thoroughly enjoy visiting the Frenchs Road Nature Reserve. The site consists of 34  hectares of remnant forest along Seabrook Creek, not far from Somerset and Wynyard in Tasmania.

Quoting from the sites information brochure:

The native vegetation of the Reserve is predominately of two types:

•  Dry Stringybark (Eucalyptus obliqua) forest on the drier and low nutrient slopes with Tea Tree and Wattle.  
• Wet (Stringybark ) forest in the lower areas and along the creek (riparian zone). This wet forest understorey consists of majestic tree ferns with epiphytic ferns, tall blackwoods (Acacia melanoxylon) Tasmanian Pepper and the occasional Sassafras and Myrtle-Beach.

The purpose of my visit was simple. No, not ferns. Birds! I was particularly looking for Pink Robin and Scrubtit.  Unfortunately the birds had other plans for the day. There were plenty to be heard but very few to be seen aside from a Grey Fantail, a Superb Fairy-wren, and a Brown Thornbill. Honestly, that was it! I see a greater variety of birds in the town centre. Next time I'll have to go a little  earlier in the day, when the birds are more active.

Watch the video and listen to the invisible birds :-)

Despite the lack of avian accompaniment I still enjoyed my short walk along the damp and ferny banks of Seabrook Creek. Since the birds refused to co-operate, my attention soon moved on to the ferns  (they can't hide). I came home with several photographs needing to be identified. While reading Gouldiae's Blog recently I was motivated to learn a little more about our local ferns and this was an opportunity to get started. Currently my only reference on the subject is a small book with black and white photos from 1975. Unfortunately that book is temporarily packed away in storage so I resorted to the Internet to identify them. Feel free to offer corrections :-)

Kangaroo Fern - Microsorum pustulatum

Fishbone Water-Fern - Blechnum nudum

Scrambling Coral Fern - Gleichenia microphylla

Bat's wing fern - Histiopteris incisa

Manfern or Soft Tree Fern  lining the bank - Dicksonia antarctica

For a "A Closer Look at at a Fern", click here.

Linked to Our World Tuesday

Wildflowers

I took a wee walk up the back hill today to photograph some of the plants which are currently flowering as well as some that are already setting seed. Here's what I found:

(Click on Photos to Enlarge)

#1 - Pale Flaxlily - Dianella longifolia

#2 - Heartleaf Bushpea - Pultenaea daphnoides


#3 - Heartleaf Bushpea - Pultenaea daphnoides


#4 - Forest Daisybush - Olearia lirata

#5 - Sag- Lomandra longifolia

#6 - Native Pigface - Carpobrotus rossii

#7 - Manuka - Leptospermum scoparium

#8 - Hop Native-primrose - Goodenia ovata

#9 - Large Kangaroo Apple - Solanum laciniatum

#10 - Sunshine Wattle - Acacia terminalis

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Wattle Apple-gall Wasp

.....Trichilogaster sp.

Apple-galls in the inflorescences of Acacias are caused by wasps which lay there eggs in the young flower buds. These wasps belong to the genus Trichilogaster of the family Pteromalidae. Some species are known to lay up to 400 eggs. When they do so, they also inject chemicals which cause the woody growth known as a gall. The wasp grubs then feed on this plant material from within. Eventually they will pupate and then eat their way out. The adult females are short lived surviving just 2 - 3 days.

As you may imagine, there is potential here for a lot of stress and damage to the tree as well as a reduction in it's ability to set seed. For this reason one species, T. acaciaelongifoliae, has been introduced to South Africa as a biological control agent for Acacia longifolia. So, you may wonder why our own Acacias are not being wiped out. It's because we have something the South Africans don't want. There are a range of parasitic wasps that keep the gall wasp population in check. These lay there eggs in the galls and there grubs feed on the gall wasp grubs. OK so what stops the parasites from wiping out the gall wasps? Simple - we have a range of hyperparasites which keep the parasitic wasps in check. In fact, in one study, "twenty-one insect species were reared from galls formed by Trichilogaster acaciaelongifoliae on Acacia secies in Tasmania".

There are at least 10 Trichilogaster species in Australia. From what I've read, T. trilineata is the most likely species to seek out Acacia dealbata an so it is the most likely candidate for the galls below which I photographed at Latrobe the other day. You'll notice in the photos that the plant is making a pretty good effort at flowering despite the galls but they will not set seed.

(Click on Photos to Enlarge)

Wattle Apple-galls on Acacia dealbata

Wattle Apple-galls on Acacia dealbata

References:

• Bashford, R. 2004, The insects associated with galls formed by Trichilogaster acaciaelongifoliae (Froggatt) (Hymenoptera: Pteromalidae) on Acacia species in Tasmania. - Australian Entomologist, 2004 (Vol. 31) (No. 1) 5-12 - Entomological Society of Qld

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Clematis in Bloom

.....Clematis microphylla

While at the Narawntapu National Park on Friday there were clematis plants in full bloom all through the scrub behind Bakers Beach. I've included a few shots below. It is Clematis microphylla and it has the most unimaginative common name ever - Short Leaved Clematis.

(Click on Photos to Enlarge)

Clematis microphylla - Short Leaved Clematis

Clematis belong to the familiy Ranunculaceae. There are 5 native species of Clematis in Tasmania plus one introduction. They are:

• C. aristata
• C. clitoroides
• C. decipiens
• C. gentianoides
• C. microphylla
• C. vitalba (Introduced)

....and for today, that's your bloomin' lot

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Fern Glade and the Emu River (Photos and Video)

...a short walk along the river.

Fern Glade and the Emu River are located on the eastern end of the city of Burnie. The steep slopes of the Emu River valley have protected the area from being cleared. It's easy access makes it a great spot to explore. Among other things, the Fern Glade Management Plan lists 30 orchids, 12 millipedes, 9 snails and slugs, 10 mammals with a further 13 mammals listed as likely to occur. Surprisingly it only lists 15 birds, the list itself being lifted from another report which is a bit lazy as you could easily list 15 species in under an hour.

I took a short walk there this morning. I was hoping to have another go at photographing a platypus but they were not cooperating today. The only mammals I saw were a Pademelon and a Staffordshire terrier (along with it's owner). A pair of Wedge-tailed Eagles were flying high overhead. Also a pair of Sulphur-crested Cockatoos which you can hear in the background in the video below. My companions spotted a Pink Robin. I was content to see a Dusky Robin (see photo). There were also, Yellow-cheeked Honeyeater, Grey Fantails, Tasmanian Thornbills, Green Rosellas and more. The Sundew, Drosera peltata was widespread along the sides of the track and we also found three, possibly four, species of orchids. The video runs for around two minutes and will give you an idea of the surroundings.

(Click to Enlarge Photos)

Emu River from a lookout along the track.

Sundew - Drosera peltata

Dusky Robin - Melanodryas vittata

Greenhood - Pterostylis sp.A

Greenhood - Pterostylis sp.A


Greenhood - Pterostylis sp. B

Mayfly Orchid - Acianthus caudatus

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Coast Needlebush

...Hakea decurrens

The University of Tasmania's Key to Tasmanian Seed Plants states that Hakea decurrens (formerly H.sericea) is "an uncommon shrub found in Tasmania only in the Furneaux Group (Cape Barren, Clarke and Flinders Islands)". The book 'Living with Plants' by McLeod & Gray says Hakea sericea was was once widespread between Burnie and Devonport but now can only be found at Rocky Cape National Park. I cannot find any other reference to the plant being at Rocky Cape. However, it is not hard to imagine a widespread loss of coastal heath species between Burnie and Devonport as the Bass Highway and the Railway line run right along the coast for much of the route between these towns. In any case, my little bit of north-west coast has three plants which I purchased from a Tasmanian native plant nursery last year. All are doing well. They flowering peaks in July and August so they will provide plenty of winter nectar for the honeyeaters.

Note: This plant is much more widespread in N.S.W & Vic

(Click images for larger versions)

Coast Needlebush - Hakea decurrens - Inflorescence

Coast Needlebush - Hakea decurrens - Fruit

Coast Needlebush - Hakea decurrens - Leaves

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