The Goodeniaceae is a predominantly Australian family and is characterised by a specialised cup-like structure at the apex of the style known as an indusium, which collects pollen as it pushes past the stamens in bud and functions as a pollen-presenter. The corolla has five lobes, each typically with wing-like extensions that are infolded in bud, and the lobes are arranged in various configurations to produce two-lipped, fan-shaped or other flower types.

A recently published paper by Kelly Shepherd of the WA Herbarium in conjunction with five other researchers will result in name changes for eight of the 86 species currently listed in the SA Plant Census for the family Goodeniaceae. The paper (downloadable here) is the culmination of a series of collaborative studies investigating relationships within the Goodeniaceae using next-generation sequencing across nuclear, chloroplast and mitochondrial DNA.

Analysis of the molecular data grouped some other genera and species of Goodeniaceae within the largest genus, Goodenia. Maintaining monophyly requires either that Goodenia be divided and new genera erected, or else its definition be expanded to incorporate those new elements. The authors made the pragmatic taxonomic decision to adopt an expanded Goodenia, which minimises the number of new names. For South Australia this means that Velleia (6 species), Selliera (1 species) and Scaevola collaris will be transferred to Goodenia, and those existing names placed in synonymy.

As amended, Goodenia now contains 230 species (54 in SA) and can be defined by various combinations of characters, although not by the development of any obvious advanced character held in common. Shepherd et al. (2020) also revised the infra-generic classification of Goodenia to better reflect its internal phylogeny, recognising three subgenera and 10 sections.

South Australian representatives for some of these groupings are illustrated below and provide a glimpse of the great floristic diversity in this genus.

Subgenus Goodenia, section Goodenia

Goodenia ovata, is the ‘type species’ of the genus Goodenia and shows the yellow two-lipped flower type found in most of the SA species.

Goodenia radicans (formerly Selliera radicans). This is the most widely distributed of the Goodenia species and is found in Australia, New Zealand and Chile. Its extra-Australian occurrences presumably result from long-distance dispersal and are not surprising given that it has sticky, fleshy fruits and occurs in swampy habitats frequented by migratory birds. The fan-shaped flowers resemble those found in Scaevola.

Goodenia collaris (formerly Scaevola collaris) is closely related to the above; it also has fan-shaped flowers and specialised fruits, which in this case are woody. It is associated with gypseous soils and with clays adjoining temporarily inundated areas.

Goodenia saccata is endemic to northern Flinders Ranges and has strongly scented white flowers similar to those in G. albiflora but differs in a number of characters including its more shrubby habit.

Subgenus Goodenia, section Rosulatae

Like many of the species in this section, Goodenia glabra often grows as a simple rosette-leaved herb, but sometimes it can develop a more bushy habit as in this example. It occurs on both rocky and sandy habitats and in SA extends from the Gawler Ranges to the far north-west of the State.

Subgenus Monochila, section Velleia

The former genus Velleia now resides in its own section of Goodenia. Its species differ from most others of the genus in having the ovary to a large degree superior.

Goodenia arguta is widespread on loamy soils in mallee and dryer woodland areas of the State. Goodenia connata, with its distinctive perfoliate leaves, occurs on sandy soils. It is most common in northern parts of the EP and MU regions and often appears after fire or other disturbances.

Shepherd published a new name, Goodenia capillosa, for the species formerly known as Velleia hispida, because the name “Goodenia hispida” had already been applied to a different Goodenia species. The main distribution of G. capillosa is in Western Australia, but there are small outlying occurrences in SA at Mt Finke (GT) and in the Indulkana Range (NW).

Subgenus Monochila, section Scaevolina

Goodenia ramelii. This striking species is found on rocky substrates in the ranges of central Australia. In SA it is restricted to the northern part of the NW region.

Subgenus Porphyranthus, section Ebracteolatae

Most species in this large section lack bracteoles on their flower stalks. Goodenia heterochila is distinguished by the highly modified upper corolla lobes, and the epithet is derived from the Greek heteros (different, other) and chilos (lip). In SA it is confined to the NW region.

Subgenus Porphyranthus, section Porphyranthus

Species of this section have small flowers and seeds and are differentiated by their numerous ovules being scattered over the surface of the placenta rather than arranged in two rows. In SA, Goodenia modesta is mainly found on low-lying flats and drainage areas of the NW and LE regions.

Contributed by State Herbarium botanist Peter Lang.

International Fascination of Plants Day, 18th May, has been celebrated since 2012 and has provided a focus for plant enthusiasts to share their interest and passion for the amazing world of plants. Last year events across 51 countries were held. While we are still primarily working from home the Staff and Honorary Research Associates of the Science and Conservation programme at the Botanic Gardens and State Herbarium (South Australia) decided to celebrate by sharing some of the plants they find fascinating!
Enjoy!
Michelle Waycott
Chief Botanist

Griffithsia monilis, a small, annual alga with delicate chains of ruby coloured cells, looking like sweets good enough to eat, spectacular under the microscope—Bob Baldock
Cephalotus follicularis (Albany Pitcher Plant), is a single species in its own family and endemic to near where I grew up in south Western Australia. These carnivorous plants are fascinating because they are not closely related to any of the other carnivorous plants such as Drosera (sundews)—Michelle Waycott
Ginkgo biloba, Royal Botanic Gardens Kew, on its 250th anniversary in 2012, with admiring cohort of ‘geriatric teenagers’—Pam Catcheside
Capparis spinosa ssp nummularia, I’m fascinated by the way the flowers change from bright white (to attract pollinators at night) to pink once its too late—Helen Vonow
Rhizanthella gardneri, an underground orchid. These fascinating plants flower where no-one can see them and only some animals can find them—that’s not an orchid! —Robyn Barker	CC BY 2.0 Fred Hort
Ptilotus sp. (mulla mulla), amazing combination of texture, colour and shape in this smoky pincushion—Teresa Lebel
Two bearded orchids from Mark Oliphant Reserve. One is Calochilus robertsonii, a bearded orchid. The other is Pterostylis plumosa, a bearded greenhood. Both are trying to trick insects into pollinating them. I like the thrill of the hunt of trying to find them 🙂 —Andrew Thornhill
Reflections—an ordinary little stump can be turned in to an intriguing complex pattern—Teresa Lebel
Acrotriche fasciculiflora (Mt Lofty Ground-berry) is fascinating for its cauliflory, with flowers packed around the base of its main stems, an adaptation for pollination or fruit dispersal by small vertebrates perhaps?—Peter Lang
Washingtonia robusta (Cotton Palms), native to Mexico, can be seen emerging from the skyline in older suburbs and rural towns in drier districts. An occasional though generally benign weed, it appeared in gardens and parks in the later 19th and early 20th centuries—Laurie Haegi
Tillandsia ‘Houston’ (T. stricta x T. recurvifolia) are fascinating because of their novel growth habit (air plants) and because they lend themselves so readily to decorative use around the home—Manfred Jusaitis
Hakea aenigma, found only on the western lateritic sands of Kangaroo Island, is sterile and unable to fruit. It resprouts after fires from suckers over distances of more than 30 km. A single plant that is an evolutionary dead-end but surviving for perhaps thousands of years—Bill Barker
Nuytsia floribunda, The West Australian Christmas Tree, is a parasitic plant that is actually a mistletoe! It has a unique way of parasitising the roots of nearby plants, a set of hard and sharp ‘shears’ cuts through the root so Nuytsia can attach feeding points to enable it get water and minerals from its hosts—Ainsley Calladine

 

 

Seaweeds − best called algae as they are not usually pest plants − are increasingly newsworthy. Browse through Chinatown food stores and they can be found advertised both as tasty additives to Asian cuisine and as healthfoods, providing Omega oils, iodine and potassium supplements to diets. If you find a number from 400 to 407 listed on your chocolate bar, milk drink, can, bottle or jar of food then the substance it denotes comes from a brown or a red alga. These algal additives keep food from separating out and looking “gluggy”.

The bright red colour of some canned foods has almost certainly been improved by the addition of an extract of single-celled green algae that have oversized red eyespots made of carotene, similar to the stuff in carrots. It should be listed on the can as 160a.

A while back, information on green algae that can be cultured in order to extract biofuel was newsworthy, although the viability of such a scheme has its sceptics.

Recently, articles appeared about a red alga that lowers methane production by bacteria in ruminant livestock (cattle, sheep, goats) in Australia. Methane far exceeds the warming effects of CO₂ on the atmosphere, so any decrease in the contribution of methane to the air by millions of ruminants would be most useful._. There are numerous articles available on this possibility but also some warnings about the alga’s potential toxicity.

So, what is this new “seaweed star”? A fluffy Red alga, about 250 mm tall, widespread in southern Australian and warm to tropic seas globally, probably introduced to the Mediterranean and Atlantic seas. It is Asparagopsis.

There are possibly 3 species, but one has been recorded only in 1945, so we can concentrate on the two common ones – Asparagopsis taxiformis and A. armata – that are being researched as methane suppressants.

Serious divers will recognise encounters with A. armata, its specialised barbed branches clinging annoyingly to wetsuits. Magnified, the effectiveness of the barbs in dispersing this species that lives attached to other algae – an epiphyte – can be appreciated. A. taxiformis is attached to hard surfaces, and has no barbed branches.

A surprising structural feature of both species is that they are made of threads or filaments, best seen under the microscope at tips of plants before the addition of cells that wrap or corticate the initial threads. These filaments can be found internally, even in mature branches, if a lengthwise section is investigated microscopically.

Perhaps more surprising about the two species is that they are sexual stages only. In Asparagopsis taxiformis both female and male structures are produced on the one plant, i.e. it is monoecious. Asparagopsis armata supposedly has separate male and female plants, a dioecious condition, but some question the reliability of this fact.

You may know that practically all Red algae have a life cycle that alternates between a sexual stage and an asexual or spore-plant stage. In the case of an Asparagopsis species, the spore stage is tiny, unobtrusive, epiphytic and so different to the sexual stages that originally it was thought to be a separate genus – Falkenbergia. It too has a thread-like construction, but largely lacks the cortication of the sexual phase.

Both stages of Asparagopsis – sexual and asexual – have been identified here and in the Mediterranean. Both sexual and asexual stages produce the methane inhibiting substance, bromoform. As the name implies, bromoform is analogous to chloroform (substitute Cl with Br in the formula). It too has a sweet, antiseptic smell like chloroform and has been synthesised in the past for industrial uses, including as a solvent, fire retardant and sedative. It may however have harmful effects on ozone, if released into the atmosphere, and possible carcinogenic effects.

As an economic retardant to ruminant methane production there are a lot of scientific and economic considerations to be made. Cropping of sporadic, naturally occurring populations of Asparagopsis would not be a viable proposition, but, fortunately plants can be grown vegetatively, so the focus of research now seems to be on aquaculture and the feasibility of doing this in vast saltwater land ponds required for the production of the quantities that would be required.

Commercial interests aside, Asparagopsis, with its intricate anatomy and cryptic life history, remains a fascinating red alga and worthy of investigation.

For additional descriptions and illustrations of species, see the following Algae revealed fact sheets:

• Falkenbergia – Step 7b and Figs 22-24 in the Filamentous red algae Master Key (2.6mb PDF)
• Asparagopsis armata (0.7mb PDF)
• Asparagopsis taxiformis (0.5mb PDF)

Written by State Herbarium Hon. Research Associate Bob Baldock.