I'll stick my neck out and say grow whatever you want, taking ino account your climate, of course.
Slightly acid clay, reasonably drained, in a mild climate sounds great to me. Do you use mulch and compost? I'm sure you've heard it before, but those two can make a massive difference.
Just checking... 'clay' means different things to different people and Brazil might have some unique conditions I don't know about. For eg was your garden area originally rainforest?
Ex-rainforest soils are usually extremely infertile.

I have very hard clay soil and anything I plant in it thrives, from annuals, vegetables, perennials, and woody shrubs and trees. It is also well-drained and slightly acid. Other than keeping a two to three inch layer of mulch over the top of beds and free standing trees, I don't do anything. The mulch disappears rather rapidly, I must say, and I'm sure the soil is being 'improved' without much help from me.

My clay dries so hard that it 'clangs' when I put a shovel to it without a thorough watering first.

I prefer the clay over extreme sand any day.
A repeated use of wood chip mulch ( not decrotive bark) and or compost will amend the soil just fine. The layer of mulch will aid in holding moisture and increase the soil biology at the same time. During dry spells try and keep the soil at a slightly moist state. Over time less and less additional water will be needed. Just set back and let the bugs do it.

Nobody has suggested any plants yet.

"I get a little fed up with garden experts telling me how to improve my clay soil"

Me too ;)

Topdress with good compost then mulch, let sit for a year (hey you said you dont like digging, this will make your clay living workable soil, not needed to be tilled much do to microbe population) and you will a perfect area to grow.

"Nobody has suggested any plants yet."

It starts at the roots.

Good day.

Sunflowers, cosmos, black eyed susans, zinnias, alyssums, and coneflowers have all done well in my clay.

Granted, they do even better when I amend the soil.

You aren't seriously trying to get good advice for a tropical paradigm in a north-american forum?

Te aviso que falar com seus vezinhos, ou busca para um foro no brasil.

Oh my, I just realized you're in Brazil!

Please ignore my previous post. You're going to need to get advice from someone local.

Certainly you can grow many plants in clay soils. People do that all the time and many simply fling some synthetic fertilizers around and then have to spray poisons to keep insect pests and plant disease away.
However, any plant will grow healthier and stronger in a soil well amended with organic matter, a soil the plants roots can stretch out and find the nutrients and moisture it needs to grow.

Acha que aquele gente ultimo sabe algo no producao das colheitas tropicais? Acho que nao.

Thanks SSM for your plant suggestions. You are the first to make any. Actually the ones you suggested are just exactly the ones I have already, except Coneflower. Rudbeckias, which are closely related, do very well, however and there is an excellent wild species that grows to considerable size.

Why is this a North American forum? I thought the internet was international. Our climate is same as Florida/ Hawaii.

I'm not American and I don't think that's the issue. I think it's more that the people who have replied to your thread don't share your climate and/or soil type, so aren't keen to make plant recommendations.
What do people around you grow? I imagine solanums and cucurbits might do well. Okra? Southeast Asian greens? Sweet potato?
I know nothing about flowers in your climate.

Well, it is surely a temperate-climate forum.

Since it's pretty clear that you are a transplant from an english-speaking country (IOW, temperate climate), then the plants that you already had in mind might be indicative of your preconceptions. Do you not understand Portuguese sufficiently to get advice from local experts?

Fraser, there must be a huge variety of indigenous species that do well in your clay soil and frost-free environment, such as that wild rudbeckia you mentioned. Your climate might be similar to Hawaii, but I certainly can't grow what you can in Hawaiian or Floridian clay.

You might want to post in the tropics forum and ask which tropical plants do well in unamended clay.

You want a list of plants that will grow well in clay.

Sorry, it doesn't exist, and if it did, it wouldn't be same for two neighbors on opposite sides of the street. Because at the end of the day, however many articles and books you read, the plants don't read the same books, therefor they don't know where they are or are not supposed to grow. (Which for most of us, is a good thing, cuz we're always trying to push zones, modify environment (microclimate), or debate about how much sun any given plant really needs.)

I can understand wanting to have greater success, and attempting to maximize that success (especially if it saves your wallet). So you grow what you know you can, and try to add a few new things every year. If this plant does well, what is closely related to it? This is supposed to do well in this type of area, which is similar to mine, soooo...

In the end, this is a journey, not a destination. Along the way, there are surprises, heartbreaks, joys and sorrows.

Write it down as you go, and if you are able to craft a story well, you may be tomorrow's new so-called expert extolling the virtues of gardening in clay.

Thinking that the climates of Brazil would be the same as Florida would be the first mis-conception to get rid of. Where in brazil vs where in florida? Even mix-and-match I doubt you could find a pair that were comparable year-round.

Thank you to those who wrote in and made suggestions, though the majority were not helpful. In the end I decided to do my own research by going round and looking at what is doing well in some of our neighbor's gardens.I highly recommend this practice as it is also a way of getting to know them and new plants!

Our list, not by any means comprehensive, of ornamental plants suitable for minimally improved tropical and subtropical clay soil is as follows:

Abelmoschus Hedychium (Ginger Lily)
Agapanthus Helianthus
Agave Helianthemum
Aloe Helichrysum
Alstroemeria Hibiscus
Amaranthus Hippeastrum (Amaryllis)
Brugmansia (Datura) Ipomea (Morning Glory)
Buzy Lizzie (Impatiens) Lantana
Camellia (needs some shade) Marigolds (all types)
Canna Mirabilis
Candytuft (Iberis) Nigella
Cleiome Passionflowers (all)
Cosmos Portulaca
Coreopsis Physalis
Delphinium Ricinus (Castor Oil)
Eustoma (Prairie Gentian) Rudbeckia
Echinacea (Coneflower) Salvia
Frangipani Sanvitalia
Gaillardia Sobralia (Orchid)
Gardenia Sunflower
Gazania Thunbergia (all)
Gourds Venidium
Heliconia (most need shade) Verbascum
Indian Azalea Verbena
Indian Blue Sage (Eranthemum) Zinnia

It seems enough to be getting on with and I haven't even mentioned trees or vegetables! Don't worry. There are plenty I have failed with. If it's not in the list, it's probably one of them. One I forgot to mention, but they are surprisingly good are Roses. You must prune them often, however.

One tip I have found very useful. Wherever possible in clay soil sow seeds direct, working in plenty of sand into the drill. The problem occurs immediately after germination when the roots find it difficult to penetrate the dense soil, so give them a good start...and of course don't forget to water! If you'd like to know more please mail me: ifraser57@hotmail.com.

I think you had some unrealistic expectations of people on this board.
I'm glad you checked out local gardens and made a list, as that's by far the most practical action IMO.

I think thanks are in order for you feijoas for the post below since op took your suggestion and is now a complete expert.

"I'm not American and I don't think that's the issue. I think it's more that the people who have replied to your thread don't share your climate and/or soil type, so aren't keen to make plant recommendations.
What do people around you grow? I imagine solanums and cucurbits might do well. Okra? Southeast Asian greens? Sweet potato?
I know nothing about flowers in your climate."

I live in a region with hard red clay soil. The locals say that tomatoes, roses and any leaf vegetables grow well, that is to say take comparatively little effort. With some more effort you get practically everything - turnips, potatoes, carrots, squash. Nice apple orchards around here. Peaches do tolerably. But I am afraid grapes are not worth it.
I complained about my soil till I saw a monastery garden in SC - bare sand! Nightmare. They have to put a gigantic effort into it.