Penstemonoides is a rather choice salvia. The leaves do look very penstemon like. It comes from Texas. I saw it once in San Antonio Botanic Gardens taller than me but it would likely be around 1m in Australia. Flowers are a lovely maroon colour and the calcyes shaded maroon. Flowering time is autumn or late summer when it has had time to grow foliage.
It is cold hardy but probably prefers average water.
Penstemonoides is ridiculously slow to grow from cuttings, seed is the best method of propagation if you can get hold of it. It does set seed in Australia.
Not often for sale.