eric, what a cool site! my front gardens have purple and black with accents of color. it isn't funereal at all.
i have the black magic EEs --- purple heart and chinese fringe flowers.
thanks for the site link.

Weirdly, I just clicked on the link again and get a 404 error message (it must have been up for awhile, since you got there).

This is another link, with a photo of Eranthemum nigrum.

Like you, I've enjoyed growing Ipomoea batatas (the variety 'Ace of Spades' is also supposed to be good). And there is another, small-leaved purple-black groundcover that became available from seed in '03 whose name I forget, plus an Amaranthus in the T&M catalog that looks worth a try.

I just took a look at the link and it is the plant I got from "grenada" . Funny that it is listed as an Eranthemum, I always thought it was a Pseuderanthemum because its white flowers are exactly the same. The other Eranthemums do not have flowers like this plant. Could there be a mistaken identity¿

eric, here is a link to one of the seeds that i hope to order.
scroll down the page until you see it. i had no idea that goths gardened.

Here is a link that might be useful: Nemophila menziesii (penny black)

i would suggest Heuchera 'obsidian' and Ajuga 'black scallop'. both have good dark coloration.

One of my plant catalogs has a photo of a plant identical to E. nigrum, identified there as Pseuderanthemum atropurpureum. They describe it as growing to 2-3 feet with white shooting star-type flowers.

I have several cutting-grown plants which will be used either as a border accent or in pots.

i will bump this post back to the top of the list with another black suggestion.

try Canna 'australia', it's definitely one of the best.