red cestrum

Cestrum elegans
Shrub
Alternate
Simple
Red
Pink
Green

A shrub usually growing 1-3 m tall, but occasionally reaching up to 5 m in height. Its younger stems and leaves are densely covered in reddish or purplish hairs. Its alternately arranged leaves (7-11.5 cm long) quickly lose most of their hairs. Its tubular flowers are arranged in dense clusters at the tips of the branches or in the upper leaf forks. These red, reddish-pink, pink or purplish flowers (15-23 mm long) have hairless petals. Its rounded berries (8-13 mm across) turn dark pink or dull red as they mature.

Common names 
Also known as: red cestrum, crimson cestrum , elegant poison-berry, purple cestrum,
Family 
Solanaceae
Deciduous 
No
Flowering time 
year round
Native/Exotic 
Exotic
Origin 
Native to Mexico
Notifiable 
No
Council declaration 
SIL – Special Investigation List
Known distribution 

Naturalised mainly in Victoria, but also occasionally found in the coastal and sub-coastal districts of central and northern New South Wales and in south-eastern Queensland.

Habitat 

A weed of rainforest gaps and margins, wetter open forests, roadsides, gullies, urban bushland and riparian vegetation.

Habit 

A shrub usually growing 1-3 m tall, but occasionally reaching up to 5 m in height.

Impact and control methods 

"Red cestrum (Cestrum elegans) invades disturbed rainforest margins, moist and wet sclerophyll forests, urban bushland and creek banks in south-eastern Australia. In these situations it displaces indigenous shrubs and small trees and restricts the habitat of native wildlife. It is a significant environmental weed in Victoria, where it is actively managed by community groups. It has also escaped from gardens in the Wollongong district, in the Southern Highlands, and at Deervale in New South Wales.

This species has recently become naturalised in rainforest margins on Mount Glorious, Tamborine Mountain and in Lamington National Park."

Stem and leaves 

"The younger stems are round and densely covered in reddish or purplish hairs. Older stems become somewhat woody in nature.

The alternately arranged leaves are simple and borne on stalks (i.e. petioles) 5-15 mm long. These leaves (7-11.5 cm long and 2.5-5.5 cm wide) are egg-shaped in outline (i.e. ovate), oval (i.e. elliptic) or somewhat elongated (i.e. broadly lanceolate) with entire margins and pointed tips (i.e. acute apices). They are densely hairy (i.e. pubescent) when young, but quickly lose most of their hairs (i.e. they become glabrescent)."

Flowers and fruits 

"The tubular flowers are arranged in branched clusters at the tips of the branches or in the upper leaf forks (i.e. in terminal or axillary panicles). Each of these densely clustered flowers is borne on a very short stalk (i.e. pedicel) about 1 mm long. The flowers have five green sepals (4.5-8 mm long) that are fused together at the base into a tube (i.e. calyx tube). Their red, reddish-pink, pink or purplish coloured petals are also fused together into a hairless tube (i.e. corolla tube) 15-23 mm long with five small petal lobes (about 2 mm long) at the tip. The flowers also have five stamens and an ovary topped with a style and stigma. The stamens consist of a stalk (i.e. filament) 9-12 mm long topped with an anther (1-1.5 mm long). Flowering occurs mainly during winter and spring.

The fruit is a rounded (i.e. globose) berry 8-13 mm across. These fruit turn from green to dark pink or dull red as they mature and contain about eight seeds."

Reproduction and dispersal 

This species reproduces mainly by seed, which are usually spread by birds and other animals that eat the fleshy fruit. However, seeds may also be spread by water and in dumped garden waste.

Similar species 

"Red cestrum (Cestrum elegans) may sometimes be confused with green cestrum (Cestrum parqui ), orange cestrum (Cestrum aurantiacum) and night jessamine (Cestrum nocturnum). It also has similar flowers to tree tobacco (Nicotiana glauca ). These species can be distinguished by the following differences:

■red cestrum (Cestrum elegans) has pink or reddish flowers and dull red fleshy berries.

■green cestrum (Cestrum parqui ) has yellow or greenish-yellow flowers and black or purplish-black fleshy berries.

■orange cestrum (Cestrum aurantiacum) has orange or orange-yellow flowers and whitish fleshy berries.

■night jessamine (Cestrum nocturnum) has pale yellow or greenish-yellow flowers and whitish fleshy berries.

■tree tobacco (Nicotiana glauca ) has yellow flowers and dry capsules that split open when mature."