A few ideas for the tropical display:
Melastomataceae – Tibouchina is pretty – yes, we might also manage Medinella.:-)
Theobroma cacao – good economic plant and nice example of cauliflory – we have hundreds of these but the greenhouse gets too cold in winter and they don’t thrive. 🙁
Is there an Annona shrub that wouldn’t get too big? – I think Pan has already planted seeds! 🙂
Vanila planifolia (orchidaceae) vanilla orchid – we used to grow this and I’m sure we could get it again. 🙂
Eichornia crassipes (Pontderiaceae) in pond – very much on my list, along with Salvinia 🙂
Old World Tropical:
Cyathea – yes, I’d like to get these 🙂
Marrataceae fern – Angiopteris already on my wants list – no free source yet. 🙂
Rubiaceae – Coffea arabica – we already have this and will lift it and replant 🙂 🙂
Sinningia or Streptocarpus (Gesneriaceae) are pretty – yes but there are more truly tropical genera Aeschynathus comes to mind.
Pandanus (would also fit in small holding as used for textiles food and medicine) – great idea there are some smallish species
Musaceae – we have 🙂
Diascorea – we have 🙂
Manihot – Euphorbiaceae – (Cassava) – we did have but it gets very big – perhaps one for me to revisit?
Curcuma longa (zingiberaceae) tumeric – has so many medicinal, culinary, dye and ceremonial uses deffinantly a useful plant. – we have a pot of this 🙂
Platycerum bifuricatum – nice epyphitic fern – yes, this and Asplenium nidus would both be good additions.