pronounced KASS-ee-uh bye-kap-soo-LAIR-iss

Cassia, Winter Cassia, Butterfly Bush

The Winter Cassia (Cassia bicapsularis or Senna bicapsularis) is a winter bloomer that puts on a wonderful floral display around the holiday season (although photos below were taken in early May).

The flowers are also very attractive to bees and butterflies and a favorite food plant for the larvae of sulphur and white butterflies. The plant, a member of the Royal Poinciana family, can be found in almost all the tropical areas of the world. The tree can be kept as a potted specimen with judicious pruning. Makes an excellent small specimen for limited-space areas such as street sides or parking lots.

YOUNG CASSIA TREE

A concerned FloridaGardener.com reader wrote: “Senna bicapsularis is a Category 1 exotic invasive that displaces native vegetation in tropical hammocks and coastal areas. It reseeds readily. Try Senna mexicana var. chapmanii or ligustrina instead and do Florida a favor — both of these are natives and belong here.”

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Actually, Cassia (Senna) bicapsularis is an erroneous synonym for Senna pendula var. glabrata which IS a noxious invasive. Senna bicapsularis however is not in the FEPPC lists which is why Cassia bicapsularis is not prohibited for sale in Florida.

But, unfortunately it is documented that Senna pendula var. glabrata is “often sold as C. bicapsularis (Isely 1990)”.
It is easy to understand why, although it does not excuse the practice, Senna pendula var. glabrata will grow very
easily from seed while Cassia (Senna) bicapsularis has a hard seed coat which needs mechanical scarification to
sprout successfully.

Because of the confusion of the two plants (and unscrupulous growers not helping the matter) my suggestion is
that native cassias should be planted instead. Some good suggestions are:

Bahama cassia (Cassia bahamensis, now Senna mexicana var. chapmanii)

Partridge pea (Cassia fasciculata, now Chamaecrista fasciculata)

Privet cassia (Cassia ligustrina, now Senna ligustrina)

Sensitive plant (Cassia nictitans, now Chamaecrista nictitans var. nictitans)

CASSIA BICAPSULARIS FLOWERS

Plant Facts:

Common Name:  Cassia, Winter Cassia, Butterfly Bush

Botanical Name:   Cassia bicapsularis or Senna bicapsularis

Family:  Caesalpiniaceae 

Plant Type:  Deciduous tree north of Zone 10

Origin: Tropical America 

Zones: 9 – 11

Height:  12′

Rate of Growth: Fast

Salt Tolerance: Low

Soil Requirements:  Sandy-loam, well drained soil

Water Requirements: Moderate

Nutritional Requirements: Balanced liquid fertilizer monthly

Light Requirements: Full sun

Form:  Multi-stem upright shrub or small tree

Leaves:  Dark green, obovate, three to five pairs

Flowers: Deep golden yellow

Fruits: Pods

CASSIA BICAPSULARIS SEED PODS

Pests or diseases:  None major

Uses:  Specimen plant, shrub

Bad Habits: Flowers attract many bees and butterflies

Cost:  $$ — Very reasonable

Propagation:  Seeds, very easy, pour boiling water over them and allow to soak overnight before planting or scarify hard seed coat with sand paper then plant in potting soil

Sources: Tropical Look; an Encyclopedia of Dramatic Landscape PlantsFlowering Trees of Florida

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