The most spectacular Section of Iris - the different species might look very different while other are hardly to tell apart from an other - the size of the plants may vary from just a few centimeters in the smaller species up to one meter for the larger ones. Many species have very large flowers.
Unfortunatly most of those species do not belong to the easy garden plants and require specific conditions. I started to grow species of this section several years ago when a german friend gave me some plants - my goal is to build up fertile groups (by seeds) of a few species and help to maintain them in cultivation as many species are endangered in their natural habitats.
In my experience it is much better to grow this species from seed than to buy (expensive) Rhizomes - seedlings are much easier to establish and sane. Rhizomes might be digged out in nature. It would be a very sad if those should extint because someone wants to enjoy their beauty in the garden.
Growing Oncos from seed can take time as they rarly germinate the first year. There are differnt ways to let germinate seeds faster, but also the risk to loose them is also higher. Actually I returned to natural germination.
Here Examples for Plantlets in Embryo Culture and Forced Germination
Natural germinated plants
Here some cultivated species