The Fabaceae (pea family) is the third largest family worldwide¹. Fabaceae are recognised from their distinct flower of one large top petal or standard, two wing petals and two keel petals, the leaves are alternate and trifoliate, palmate or pinnate with stipules and the fruit is a long seed ‘pea’ pod. All species are able to fix nitrogen through a symbiotic association with root nodule bacteria¹.
The Fabaceae have many growth forms illustrated here by examples from the University campus.
Red Clover (Trifolium pratense)
Red clover is a perennial grassland herb, 10-40 cm tall, with dense heads of small purple flowers and hairy, trifoliate leaves.
Red clover is common in most of the grasslands on campus and elswhere is a widely planted forage species which can improve or restore soil fertility and is an important nectar resource for butterflies, bees and moths².
Research suggests that with an increase in temperature and CO2 levels its frequency may increase in grassland ecosystems³.
Common Broom (Cytisus scoparius)
Common Broom is a branching deciduous shrub growing up to 1.5 m tall with large yellow flowers in May to June. This plant grows under trees along the lakeside path on the north-west side of the University campus.
All parts of the plant are toxic if ingested and in Australia, New Zealand and the USA it is considered an invasive non-native species4.
Tufted vetch (Vicia cracca)
Tufted vetch is a downy, climbing perennial, 60–200 cm tall, with purple flowers in racemes above the pinnate leaves. The leaves have branched tendrils which assist it in scrambling over other plants and vegetation.
Tufted vetch is found in the campus grasslands especially on the western side of the lake and is very attractive when in flower from May to June, later forming hairless brown seed pods each containing 2-6 seeds.
Images reproduced under the creative commons license.
¹Encyclopædia Britannica Online (2011) Fabaceae. Available at: http://original.search.eb.com/eb/article-9105203 [last accessed 26.10.2011].
²Royal Botanic Gardens Kew (n.d) Trifolium pratense (red clover). Available at: http://www.kew.org/plants-fungi/Trifolium-pratense.htm [last accessed 20.10.2011].
³Hopkins, A. & Del Prado, A. (2007) Implications of climate change for grassland in Europe: impacts, adaptations and mitigation options: a review. Grass and Forage Science. 62, 118-126.
4USDA (n.d) Cytisus scoparius. Available at: http://plants.usda.gov/java/profile?symbol=CYSC4 [last accessed 20.10.2011].