Monday, 22 April 2013
Not enough of these native jonquils to make a Calastemma garland
West of Merbein, on the floodplain of the Murray River, grows a population of a lily-like plant with bright yellow flowers. Not a daffodil, not a jonquil, but a native Australian plant.
Sometimes this yellow flowered bulb is considered part of a species that has mostly reddish flowers, Calostemma purpureum. When the flowers of Calostemma purpureum are not reddish (or purple I guess) they can be creamy, pink or a combination of the above. They can also be entirely yellow I gather. The Australian National Botanic Garden appears to have them all on display.
Calostemma luteum, if you accept a second species in this genus, has larger flowers, and all parts of the flower are predominantly yellow. But as you can see in these pictures, the middle tube and the radiating petals can be flushed with red. Although described from a plant in cultivation it can be separated in the field, at least if you live south of the Murray River...
In the online Flora of New South Wales, PlantNet, only one species is accepted. In the hard (and soon to be soft) copy Flora of Victoria both are accepted albeit our luteum only warranting a small paragraph at the end of purpureum - which is code for 'we are not really very confident about this' or 'this came to us a little late' (my co-editor Neville Walsh recalls it was the latter).
Calostemma purpureum and Calostemma luteum extend into South Australia and New South Wales along the Murray-Darling system, and if you accept the latter it goes all the way into Queensland (otherwise of course the purpureum thingo does and happens to be only yellow in that State...).
In Victoria both species (we accept them remember) grow in flood prone lands near the Murray River between Boundary Bend and Wentworth. The red flowered species can appear in hundreds or even thousands in a good season. That season, for both species, is February to April.
In 2008 a third (or second) species was described from South Australia, called Calostemma abdicatum. Its flowers are missing the whole tube bit, as well as being large like luteum but coloured like purpureum. So there is not much debate about this one being different to the other(s).
Our Calostemma luteum in the Royal Botanic Gardens were almost finished flowering by the time I photographed them a week or so ago (these are the fruits, or perhaps bulbils?). They live in our rare and threatened garden bed, just above The Terrace cafe, and I presume they come from the clump discovered in March 1994, the only population so far known in Victoria. It's either rather rare or rather absent in Victoria, depending on your taxonomy.
Calostemma is in the plant family Amarillidaceae, as you'd expect, in both its traditional and newer expanded form. This family in its narrowest sense also contains the daffodil and jonquil, as well the Crinum Lily and various other showy bulbs.
Any Calostemma is called the Garland Lily. The yellow flowered ones, Calostemma luteum if you like, are called the Yellow Garland Lily and in at least one case the Native Jonquil. That last name reeks of colonial servitude but it's pretty damn accurate and useful.