Cassia or Senna
Appearance: Mainly shrubs to small trees, pinnate foliage with brittle branches.
Flowers: Yellow terminal clusters, often during warmer months.
Features: Birds attracting plants.
Requirements: Tolerates a wide range of soil types. Some species are sensitive to frosts. Full sun.
Culture: Pruning improve shape and flowering. Most prefer well-drained soils.
Pest & Disease : Attacked by foraging animals (eg.possums); beetles, use carbaryl to control beetles.
Species & Varieties:
More than 500 species of cassia (though many, particularly shrub species, have now become Senna) including:
C. acutifolia (Alexandrian Senna) -Shrub to 2m tall, from northern Egypt.
C. alata -Shrub to 2.5m, green foliage, yellow flowers.
C. artemisiodes -To 1.5m tall, fine blue foliage, yellow flowers.
C. bicapsularis -Upright plant to 4m tall, thin pods to 15cm long
C. occidentalis -To 1m or taller, green foliage, yellow flowers.
The genus Cassia has been divided into two, Cassia have woody cylindrical fruit which do not break open; Senna have fruit which is flat or pulpy, and which breaks open along both sides of the two papery halves. Another way to tell the difference is that plants with terminal flowers remain as Cassia, and those with axillary flowers become Senna.
Many gardeners however ignore these changes. Some more significant changes are as follows:
Old Name New Name
Cassia alata = Senna alata
C. artemisioides = S. artemisioides
C. bicapsularis = S. bicapsularis
C. carnaval = S. spectabilis
C. coluteoides = S. pendula var. glabrata
C. corymbosa = S. corymbosa
C. didymobotrya = S. didymobotrya
C. floribunda and C. laevigata = S. x floribunda
C. occidntalis = S. occidentalis
C. tomentosa = S. multiglandulosa