Nematanthus are typically best grown in a basket as they are trailing species. I currently have N. 'Black Gold' in a 6" pot, but it's easily 18" wide at this point. Leaves are generally no more than 3/4" long and it is a good bloomer. The bright orange flowers contrast nicely with the dark foliage. It's a common hybrid that I've even seen for sale several times in big box stores.

Mark

I tried N.australis - and it is kind of sparse... bare sticks and rare leaves and flowers...
To add to Mark's recommendation - old hybrid "Christmas Holly" is compact and cheerful.

N. corticola and N. brasiliensis as well as their hybrids with large leaves do not reach their full potential unless you have 2-3 foot of space to spare.

I got a really attractive and everblooming hybrid from Michael Kartuz by the name of "Linda Joe". Love this thing!!!

Irina

Here is a link that might be useful: Kartuz collection

Below is a photo of my Nematanthus brasiliensis, taken today. It's in bud (lower right). I''m not an experienced grower of Gesneriads. A friend gave it to me nearly defoliated and I've tried to nurse it back to health. It has been growing in an area with afternoon sun only. Morning sun might be better, but those spots are limited. It has been outside, but I've experienced no frost.

"Neglect" is a good word for how I've treated this plant. I suspect it should be staked again. I think it does need to be cut back, probably a lot. This would of course generate a lot of cuttings. I'm sure it can be grown much better, but is it the right choice for someone looking for a small, floriferous plant? Probably not. This is probably a better one for those looking for the unusual, with less concern for the overall impact.

I forgot to mention. The little guys in 3 inch pots placed in the 1 gallon pot are Nematanthus fritschii, seeds from Mauro Peixoto (Brasil Plants). I don't have too much to add except that those guys are smaller, so far...

I highly recommend 'Black Gold'. It does not grow too big, blooms constantly. The flowers (to me) are more a golden orange, nice, darker small leaves. It is an easy grower, too. 'Lemon Lime' with glowing bright yellow flowers, is a great choice, too. It does not get big, but can require more pruning. If you want BIG, go with 'Champagne Jam' or 'Pretty Plum'. Both are in 7 gallon (yes that is right) pots, and I use both in the landscape.

Wow! Thank you all for the input. I guess I had no idea that some of these could get so large (7 gal.?!). Someday I do want to try a N. brasiliensis, but for now I don't have room for it. Thank you for the photo, I've been trying to find a picture of an entire plant for size reference.

I think I have it narrowed down to either black gold or Christmas holly. Linda Jo looks very cool, but the foliage is nearly identical to my Xcodonatanthus vista.