Plant of the month – Dec 2017

TALL BLUEBELL

(Wahlenbergia stricta)

(Photos: C. Schultz: Left to Right. Single plant with one flower; flower from above, flower from the side)

There are quite a lot of Wahlenbergias, all commonly thought of as bluebells. Nearly every continent has its own varieties! The bluebells at Cape Jervis are only knee high, but flower prolifically over spring and summer. You will notice the pretty purple-blue flowers waving in the breeze, above the low growing grasses and herbs. Stems are thin, with leaves often paired at the bottom but alternating further up towards the flowers. The flowers themselves are 5-petalled, normally with a tube beneath the lobes. The plants produce tubers underground which can be used to produce other plants by division. They also grow from seed or cuttings. In some Wahlenbergias both the flowers and the tubers are edible.

Weed of the month – Dec 2017

CANOLA

(Brassica napus)

   (Photos: C. Schultz; Left to right: large clump of canola plants; flowers with unopened buds; flowers and developing seed pods)

We all know canola because of the edible oil derived from its seeds, making a really good cropping plant. When mature seeds blow into coastal heath, however, this useful plant becomes a weed very quickly! An Agriculture Victoria website[1] advises that “Once established, canola is effective at crowding out weeds.” Given it can crowd out weeds in a cropping situation, it is no wonder it crowds out natives in remnant vegetation. We’ve seen this at Cape Jervis, where canola established itself in one season after weed clearing. You will spot the bright yellow flowers, which can appear even on very young plants. And you will smell them! The brassica family includes broccoli, cabbage, cauliflower and turnip… all strong smelling. The plant grows to about 1.5m tall, with an open habit of a central stem and many side branches. It has a central tap root, which with the right amount of moisture can grow 2cm a day! Remove the seed pods well before they ripen; if you just pull out the plant the seeds might after-ripen. 

[1] http://agriculture.vic.gov.au/agriculture/grains-and-other-crops/crop-production/growing-canola; sighted 10-11-17