Ipomoea cairica

Ipomoea cairica.

Coastal Morning Glory, Mile-a-minute or Five-leaf Morning Glory has also been known as Convolvulus cairicus.
It is an exotic plant that has become naturalised in Queensland where it is now weed.
It is commonly seen around Brisbane both in gardens and areas of bush.
It is a fast growing perennial plant that can smother other vegetation, spread rapidly and produce a lot of seeds.

With support it is a twining climber or trailer and without it is a dense ground cover.
The branching stems are often around 3 to 5 m long but occasionally up to 8 m.
Young green or red stems are smooth while older ones are woody and sometimes nodular.
There are no hairs other than occasional ones at the nodes.

The alternately arranged leaves are on petioles from 2 to 7 cm long.
The pseudo-stipules at the base of the petiole are small leaves from undeveloped axillary buds.
The circular leaf blades are from 3 to 10 cm long and wide.
The blade is divided, usually to the midrib into 5 or 7 ovate, elliptic or lanceolate lobes.
The lobe tips have small abrupt points or mucros and the edges may be wavy.

The basal lobes are the smallest and they are frequently divided part or all the way to the midrib.
The terminal lobe is the longest at up to 5 cm long by 2.5 cm wide and there are no hairs.

Axillary inflorescences are on a short or long stalk or peduncle (1 to 8 cm).
The 1 to 3 flowers are on a stalk or pedicel 1 to 3 cm long.
The deciduous paired bracts and bracteoles on these stalks are only a few mms long.

The 5 free concave ovate sepals, with a mucro at the tip are in 2 whorls.
The outer 2 are up to around 7 mm long and the inner wider ones up to 10 mm.
There are no hairs but tiny nectaries at the top of the pedicel just under the sepal bases produce drops of nectar.

The 5 petals are fused into a trumpet-shaped corolla tube with flaring lobes – the limb.
The tube can be up to 6 to 8 cm long and the limb 7 to 8 cm across.
It is violet or pale purple with a darker throat. Rarely it is part or all white.
The mid petaline bands, the same colour as the limb have an extended pointed tip.

The 5 stamens are inserted a few mms above the base of the corolla tube.
Of unequal lengths the 2 longest are up to 2 cm with anthers in the tube.
There are purple hairs on the filament bases.
The pale yellow nectary disc lies around the base of the superior ovary.
The smooth conical ovary has 2 locules and a style with a bi-lobed stigma that lies among the anthers.

The fruit are slightly flattened spherical capsules around 1 cm long with the sepals attached.
They mature from green to pale brown then open into 4 chambers each with 1 seed.
The dark, slightly flattened and 3-angled seeds are around 6 mm long.
They are covered in tiny hairs and have a ring of white hairs up to 9 mm long along the 2 sharp edges.

World Flora Online recognises 3 varieties differing in the width of the middle leaf lobe and the length of the corolla.