Chorizema cordatum, the Heart-leaf Flame Pea, is a woody scrambling/climbing shrub, often with many stems, capable of climbing to 2 metres or more and forming clumps up to 1 metre wide.
It is a native of south-western Western Australia, growing as far east as Albany (and north of) – west and north along the coastal areas to south of Eneabba.
It is typically found in dry sclerophyll woodland, shrubland and forest, on sandy to clayey soils with granite and laterite bases.
Chorizema are a member of the “pea” family. This generally means that leaves are alternate with stipules at the base of the petioles. In this species, leaves are alternate, to 6 cm long and 3 cm wide, ranging from ovate to oblong to heart-shaped (cordate) in shape, light to dark green and with small linear stipules at the base of the petioles.
Flowers are, of course, pea-shaped (a term sometimes used is papilionate), with 5 petals in a fixed arrangement; the main back petal is called the “standard”, two lateral petals called “wings” and two fused petals at the bottom called the “keel” (in which the anthers and one carpel tend to be hidden). Chorizema can have yellow, orange or red flowers or dazzling colour-combinations (such as in this species). In this species, flowers are produced on terminal racemes, well beyond the foliage, in clusters of up to 20 or more. Flowers are to 12 mm across are are a beautiful mixture of orange-purple with some yellow and red tones, appearing mainly in spring.
The fruit of all peas is a pod. In this species, they are to about 7 mm long by 5 mm wide and produce black seeds.
The Heart-leaf Flame Pea is a colourful small shrub that would be at home in native cottage gardens and rockeries. Tip pruning is beneficial after flowering.
From Jeff Howes in his Sydney garden:
I have been growing Chorizema cordatum for many years in my garden in the northern Sydney suburb of Westleigh and when in flower it is always commented on.
It is a small, scrambling shrub usually about a metre high by about a metre spread. I am also growing a form with pure yellow flowers and most visitors to my garden are not that impressed with the soft yellow flowers, although I happen to like it.
Chorizema cordatum is best grown as an understorey plant where its thin, weak branches can be supported by other plants. Grown on its own, as the one in the photo is, requires the plant to be staked and the branches supported, not ideal.
My plants are growing in a thin layer of topsoil over a clay sub soil that is quite well drained. I ensure they have some moisture in drier times as this plant performs much better with some moisture. I have lost most of my plants due to excessive dryness. After flowering I prune the plant back by at least one third to half. This drastic pruning ensures plenty of new growth and flowers the following year.
Chorizema cordatum is a great plant for that difficult spot in the garden that receives only dappled light and needs to be “brightened up” in late winter. If they are grown in full sun you will find the flowers fade and lose a lot of their visual impact. A ‘must have’ plant for any garden.
Propagate from seed or cuttings. We find that cuttings produce roots rapidly and they flower much sooner than seed grown plants.
There are 25 Chorizema species, all endemic to Western Australia with one exception. Chorizema parviflorum is native to NSW and Queensland. Chorizema cordatum is the most widely cultivated species.
This species likely regenerates from seed after fire.
Chorizema – several origins are reported but the most ‘considered-likely’ is from Greek Chorizo (χωρίζω) and –nema (Νήμα) (although the ‘N’ is lost in the resulting Latin combination) – meaning “thread” – referring to the separated staminal filaments in the flowers.
cordatum – Latin meaning “cordate” – generally meaning ‘heart-shaped’ – referring to the leaf shape sometimes observed.
This species is not considered to be at risk of extinction in the wild.
The thumbnail is an illustration of the type specimen named by John Lindley in 1838 and growing in the garden of Robert Mangles, Sunning Hill Berkshire UK.
The Western Australian Herbarium – Florabase: The Western Australian Flora – Chorizema cordatum profile page https://florabase.dpaw.wa.gov.au/browse/profile/8971
Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers, Pty. Ltd. Australia.
Australian Native Plants Society Australia – Chorizema cordatum profile page https://anpsa.org.au/plant_profiles/chorizema-cordatum/