T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network

Solanum wendlandii (Potato Vine)

Kingdom: Plantae
(Unranked): Angiosperms
(Unranked): Eudicots
(Unranked): Asterids
Order: Solanales
Family: Solanaceae
Subfamily: Solanoideae
Tribe: Solaneae
Genus: Solanum
Subgenus: Leptostemonum
Section: Herposolanum
Species: Solanum wendlandii 
Common names: Potato Vine, Giant Potato creeper. Paradise Vine, Divorce Vine, Giant Potato Vine, Blue Potato vine, Costa Rica nightshade.

This vine is a native of Costa Rica and is commonly grown as an ornamental plant in gardens. It is a vigorous green climber, glabrous except for hairs on corolla tips; prickles hooked, scattered on main stems and leaves or absent.  The leaves are ovate; lamina 11–22 cm long, 4–8 cm wide, concolourous (of the same colour throughout), entire or deeply lobed, the lobes often cut to midrib and lowest pair sometimes petiolulate.
Its inflorescence is terminal panicle of cymes up to 20 cm long; pedicels to 15 mm long. Calyx 4–6 mm long; lobes 2-3 mm long, oblong, cuspidate. Corolla pentagonal-rotate, 30–50 mm diam., pale lilac-blue. Anthers 10 mm long, oblong. The flowers start with a deep purple colour and then fade to lavender, then white.

Photographed at Tupare.   http://www.trc.govt.nz/tupare-home/

A variation of leaf shape

Thanks to Wikipedia for text and information: