Friends of Tarra-Bulga National Park

Friends of Tarra-Bulga National Park

Website of the Friends Group – Information about working bees and monitoring projects. As well as flora and fauna pictures and descriptions

Category: Flora

Hypolepis – Ground Ferns

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One of the trickiest groups of Ferns to identify locally are a group of Ground ferns in the Genus Hypolepis. There are three different species recorded in the park but I have only ever found two of them which are Hypolepis glandulifera (Downy Ground-fern) and Hypolepis rugulosa (Ruddy Ground-fern). Without looking carefully these ferns can be mistaken for Bracken because they have a similar growth habit with fronds popping up from a spreading underground rhizome.

Hypolepis rugulosa (Ruddy Ground-fern) seems to be more common locally at higher altitudes in the Park (e.g. Wet Forest areas around Balook). It seems to like disturbed areas at the sides of roads and tracks. Its main feature for identification in the field is the reddy-brown colour of the frond stems (Stipes).

Frond showing red-brown coloured stem (Rachis)
Frond
Ready brown frond stem (stipe) with small hairs.
Hypolepis rugulosa – Ruddy Ground Fern
Red-brown frond stem (Rachis)
New frond (crozier) not stickly like Downy – Ground-fern.
Close up of underside of pinnule. Showing little flap with a few hairs next to the sori.
Underside of fertile fronds showing arrangement of sori.
Base of frond (stipe) where it comes out of the ground, Chestnut brown with hairs.
Hypolepis rugulosa – Ruddy Ground Fern
Topside of pinnae which are slightly harsh.

Hypolepis glandulifera (Downy Ground-fern)  I have found mostly at lower altitudes, especially along waterways (e.g. Tarra River and Macks Creek). Its frond stems (Stipes) are usually a pale green colour. It usually has lots of fine hairs along the stems and the new fronds are often sticky to the touch as a result of the small glands on the tips of many of the hairs. If you have a hand lens or use a digital camera with a macro setting you can see that there is a little triangular tooth close to the sori on the underside of fertile fronds. This fern was formerly known as Hypolepis punctata.

New frond, which is sticky to the touch because of the soft glandular hairs.
Typical Frond
Close up of frond stem (stipe) with soft hairs, some of them with glandular tips.
Sori have a small tooth shaped flap protecting them. (note this photo is magnified)
Pinnules usually have rounded tips.
Showing the base of the fronds. Mostly a light green colour.
Underside of a fertile frond, packed with sori.

Hypolepis muelleri (Harsh Ground-fern) is also listed in Park’s flora records for the but I have yet to find any. It can be identified by the presence of tiny hairs growing in the Sori on the underside of the fertile fronds.

Lance, Strap and Ray the Water Ferns

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With names like Lance, Strap and Ray this lot of Water-ferns sound like rather a threatening bunch, but in reality they are probably not so tough. All preferring to grow locally in the moist shade found in Cool Temperate Rainforest. All of these species can be found fairly easily in both the Bulga Park and Tarra Valley rainforest walks. Overall seven species of Blechnum grow in Tarra Bulga National Park.

Lance Water-fern (Blechnum chambersii) like all the local water ferns (Blechnum species) apart from one have two distinctly different frond types. The ones that carry the reproductive spores on their undersides have very narrow and droopy pinnae (leaves). The regular fronds are dark green and the leaflets (pinnae) are curved and broad at the base where they are attached to the stem.

Fertile frond, narrower than than the regular fronds.
Underside of the fertile fronds showing the arrangement of the sori.
Curved pinnae with the wide bases.
Close up of the pinnae.

Ray Water-fern (Blechnum fluviatile) The regular fronds have small green oblong to oval shaped pinnae (leaflets) with rounded tips. The stems of the fronds (Rachis) are covered in scales as well as small hairs.

Regular (green) and fertile (brown) fronds.
Fertile fronds packed with spore producing sori.
Regular fronds with small rounded pinnae.
Long narrow regular fronds.
Stem (Rachis) note the scales and the fine hairs.

Strap Water-fern (Blechnum patersonii) Has regular fronds that are either one long strap or may have a few pairs of divided pinnae which can give them a similar look to Microsorum pustulatum (Kangaroo Fern). The edges of the fronds are usually wavy (undulating). The regular fronds are also broader closer to the tip (and skinnier at the base), they are quite tough and leathery and are a very dark green colour. The spore carrying fertile fronds are much narrower and can also be a single strap or have a few narrow sub-divisions.

Typical plant with long strap like fronds.
A fertile frond covered with spore producing sori.
Dark green strap like fronds.
In this case the frond is divided and looks a bit like Kangaroo Fern.

Blechnums: Hard and Soft Water Fern’s

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Another post in our series for people wanting to know more about the fern species in Tarra Bulga National Park and how to identify them. Here we look at two more species of Blechnum. Hard Water-fern (Blechnum wattsii) and Soft Water-fern (Blechnum minus).

Blechnum wattsii – (Hard Water-fern) is much more common than the Soft Water-fern at Tarra Bulga and is found in both Cool Temperate Rainforest and Wet Schlerophyll forest areas. It has tough dark green fronds, a key feature is that the lower leaves (pinnae) on each stem (rachis) are only slightly smaller than the others.

Blechnum wattsii – Hard Water-fern – Showing a typical dark-green frond
A typical spreading colony of Hard Water-fern – Blechnum Wattsii
Blechnum wattsii – Hard Water-fern – showing where the pinnae are attached by a very sort stalk
Blechnum wattsii – Hard Water-fern – pinnae – Underside of pinnae, which are also attached to the stem by a very short stalk.
Blechnum wattsii – Hard Water-fern – Underside Fertile Pinnae, which are narrow and covered in spore producing sori.
Blechnum wattsii – Hard Water-fern – Showing the narrow fertile fronds
Showing lower pinnae of Hard Water-fern at the top of the photo which are only slightly smaller than the ones on the rest of the frond.
Blechnum wattsii – Hard Water-fern – showing both fertile fronds (taller and narrower) and regular fronds.

Blechnum minus – (Soft Water-fern) is locally more restricted in its distribution and mainly confined to the banks of water-bodies. It’s fronds are a lighter shade of green and the margins of the pinnae are more undulating or wavy. A key feature of their identification is that the lower leaves (pinnae) on each stem is are much shorter than the rest and they are also widely spaced apart.

Blechnum minus – Soft Water-fern new frond (Crozier)
Blechnum minus – Soft Water-fern – Pinnae are attached to the stem by very short stalks.
The back of a fertile Soft Water-fern frond covered in spore producing sori
Blechnum minus – Soft Water-fern a typical frond
Lower pinnae of the Soft Water-fern, are much shorter than the ones along the rest of the stem and are more widely spaced apart, (the grass is covering up a another pair of pinnae even lower down the stem).
Blechnum minus – Soft Water-fern Growing in a typical situation adjacent to water.

Both species are dimorphic meaning that the fertile fronds that contain the spores are different to the regular fronds, for both of these species they are a lot more slender than the regular fronds.

Related Posts

2012 Sycamore Maple Planting Project Site Update

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Biggest Seedling
We have a winner this is the biggest planted tree I found on the site.

Recently trekked in to monitor progress I had been putting it off until the heat wave had passed. It was four and half months since I had last seen the site so I was anxious to see how things were progressing. First impressions where that there has been a lot of regrowth of under-storey the Snowy daisy-bush (Olearia lirata) had really taken off, and it was even harder to move around the site and to spot the Mountain Ash we had planted. With careful searching the good news was that the planted trees were still there and looking healthy and mostly untouched by Wallabies although I was expecting a bit more growth over summer.

Lots of re-sprouting on this Maple stump
Sycamore Maple stump with lots of re-sprouting that will need to be treated.

The other concern I had was how much regeneration there had been of the Sycamore Maple trees that had dominated this site until they were cut down cleared several years ago. When I had visited in October there were hundreds of new seedlings that had popped up since our planting day in August. I was happy to see that in the more open areas there were few if any Maples (I think the hot summer may have killed them off) it was noticeable however that some of the large stumps had varying amounts of re-shooting from the base that needs to be dealt with.

Read More “2012 Sycamore Maple Planting Project Site Update”

Do you want fries with that?

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Hopefully they won’t be a huge threat to the ecology of Tarra-Bulga National Park but it was interesting to spot this crop of potatoes that seem to have become naturalised in a small patch in the park on the roadside along the Bulga Park Rd.

Tarra Bulga Spud
Tarra Bulga Spud
Potato plants on the edge of the gully.
Potato plants on the edge of a gully along Bulga Park Road.

Blechnum Species in Tarra Bulga

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There are seven different species of the fern genus Blechnum (Water Ferns)  in Tarra Bulga National Park and with a bit of background knowledge it is relatively easy to tell them apart. This post will focus on the identification of Blechnum nudum (Fishbone Water-fern) and Blechnum cartiliagineum (Gristle Fern), which unlike the other 5 species both have leaflets (pinna) being directly attached to the regular fronds by a broad base. The easiest way to tell them apart is by their fertile fronds.

Blechnum nudum (Fishbone Water-fern) is usually found in clumps in wet forest and gullies, it is reasonably common around Tarra Bulga.

Blechnum nudum – Fishbone water-fern
Blechnum nudum – Fishbone water-fern, Showing the finer fertile fronds at the front and regular (Barren fronds) behind.
Blechnum nudum – Fishbone water-fern
Blechnum nudum – Fishbone Water-fern, showing the underside of the leaflets (pinnae) which are a paler green and are attached to the frond by a broad base. The shaft of the frond (rachis) is often a shiny black colour.
Blechnum nudum – Fishbone water-fern, showing fertile fronds which are different to the barren ones (which don’t carry spores)

Blechnum cartiliagineum (Gristle Fern) is less common in Tarra Bulga and is more commonly found in gullies or sheltered spots at lower elevations downstream from the park.

Blechnum cartilagineum – Gristle-fern, also has leaflets attached to the rachis by their broad base.
Blechnum cartilagineum – Gristle-fern, showing the lower stem (Stipe) which is grooved and has black scales.
Blechnum cartilagineum – Gristle-fern
Blechnum cartilagineum – Gristle-fern, The paired pinnae (leaflets) towards the base are separate and point downwards.
Blechnum cartilagineum – Gristle-fern, Underside of a fertile frond showing bands of sori either side of the mid-vein.

Senecios (Fireweeds) at Tarra Bulga

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Despite having weed as part of their common name and belonging to the same genus as the much maligned Ragwort (Senecio jacobaea), there are several species of Senecio in Tarra Bulga National Park that are locally indigenous and very much desirable. They are most commonly found in open and disturbed areas, usually where there is a break in the canopy or on the side of  roads and tracks. Their ability to quickly colonise an area like this means they can compete against real weeds that may potentially invade these sites.

Senecio linearfolius (Fireweed Groundsel) grows to about 1.5 metres high and usually has smooth narrow lance shaped leaves with regularly spaced teeth. When in flower it can be identified by the 5 yellow ray florets (like petals) on each flower head. The flowers heads are clearly different from the other species that exist in the park (described below).

Narrow shiny leaf with toothed margins.
Can usually be identified when if flower by the 5 yellow ray florets (that look like petals) on the individual flower heads.
The base of the leaves taper to a point at the base.
The underside of the leaf is smooth.

Senecio pinnatifolius (Variable Groundsel) is an amazingly variable species with huge differences in the size and form of the plant possible. What is consistent however is the attractive flower heads which are wider than the other species (up to 15 mm across) and have up to 14 yellow (petal like) ray florets, The unopened flower buds are bell shaped. The foliage is so variable that it is not useful for identification apart from the fact that the leaves are sessile (which means they are connected to the stems without a stalk) and it is usually hairless.

The leaf shape and size is very variable, it is usually hairless and always attached directly to the stem without a stalk (petiole).
With is attractive flower heads, not it has up to 14 yellow ray florets (like petals) while Senecio linearfolius usually only has 5.
Attachment of the leaf to the stem.
The unopened flower buds are bell shaped and look like this one the flower has opened up.
An example of the amazing difference in the foliage, this one was photographed only metres away from the one photographed above.

Senecio minimus (Shrubby Fireweed) has more consistent leaf characteristics so you can usually easily identify it without seeing its flowers. The leaves are lance shaped and have evenly spaces small raspy teeth on the margins. Where the leaf base is attached to the stem there are two lobes (auricles). The stems themselves have vertical ridges and are usually quite purple. The flowers heads are clearly different from the other two species. There are large clusters of them at the end of flower stalks but they do not have any petal like ray florets.

Underside of the leaf
Has consistently the same shaped leaves with small raspy teeth all the way along the margins.
Flowerhead
The base of the leaf where it attaches to the stem with the pair of toothed lobes called auricles.
Close up of the flower heads.
The stem is purplish and has prominent ridgelines.

Senecio jacobaea (Ragwort) is a noxious weed, sometimes found in disturbed sites in Tarra Bulga, but it is far more common in in cleared farming areas nearby. It has similar looking but smaller flowers when compared with Senecio pinnatifolius, but it has distinctive deeply lobed leaves which make it clearly identifiable.

Distinctive looking divided lobed leaves.
Flowers.