Hi folks, yes, it is a Prostanthera cuneata, one that I purchased in Portland, OR at the WWSW in 2008. I keep three species of Prostanthera in my cool greenhouse, they do so well since they can handle a little freeze every now and then ( when the gas runs out!). The diascia is not hardy here, I purchase young plants in late winter, and they bloom until mid-July, when it gets hot and humid.
USDA Zone 5B
I've enjoyed the comments about Rhodohypoxis hardiness: obviously much to learn there...
Many Diascia are moderately hardy in Denver if pampered in a perfect site and soil: after all, the perennial sorts almost all come from high altitudes in the Drakensberg...
BUT One species is Very Tough: Diascia integerrima, particularly in the dwarf race that was introduced through Plant Select called 'Coral Canyon' is tough as nails. I've been ransacking my computer (apparently I don't have pictures on it here..dammit!) but there are lots on the internet: check out this URL:
I collected seed from which 'Coral Canyon' was selected in 1998 with Jim Archibald a short distance above Rhodes on the way to Naude's Nek in the East Cape mountains (very cold area). Typical integerrima can get to be a yard tall, this race stayed much more compact, in the wild only a foot tall or less. In the garden it can get bigger, especially in rich soil. It has persisted for ten years in some sites for us here, and is one of the most long blooming and gratifying perennials. Many Plant Select cooperators sell plugs: you must try it!
For every minion of the peaks there are a dozen steppe children growing in the dry Continental heart of all hemispheres still unknown to horticulture.
Some Diascias even make nice plants in Northern Norway and are sold by nurseries far north:
They sell Delosperma basuticum too:
Rogaland, Norway - with cool, often rainy summers (29C max) and mild, often rainy winters (180 cm/year)!