A couple of years back a friend gave me some seed labelled Portuguese cabbage.
I grew some seedlings and planted one out at the allotment alongside some other heritage brassicas such as Sutherland kale, Madeley kale and Delaway cabbage. At first I grouped it with these others in my mind also; broadly similar leafy brassicas which nonetheless offer up interesting individual characteristics in leaf form and colour, flavour, heat and cold tolerance, disease and pest resistance.
Meanwhile I was trying to lay my hand on some cuttings of tree collards from the United States, having heard that they are 'true' perennials, like Daubenton kale, in that they rarely flower and keep growing for several years. (Many brassicas will keep growing after their second year flowering, especially if you remove the flowers as they appear. But I have found that this can be a lot of work - they are often really keen to flower, managing to replenish their flowers just a few days after the last lot have been removed - and that during this enthusiastic flowering phase they produce fewer and smaller leaves.) I couldn't find anyone who would send tree collard cuttings to England but in searching the web I found a comment that Portuguese kale/cabbage was the European equivalent of the tree collard.
I inspected the one Portuguese kale I'd grown with renewed interest. It was impressive! It was growing fast and had very frilly, large, thick, grey-green leaves of mild flavour with prominent white midribs and veins, growing from the top of a two foot stem. It looked very distinctive - and very distinguished - amongst the heritage kales.
It is not easy to say for certain but comparing this kale to photographs on the internet it looks similar to those described as 'couve galega'. Frillier than some, admittedly, but I understand couve galega to be the name for a landrace plant, a genetically diverse variety of a domesticated species that is adapted to local conditions. So frilly and non-frilly may be all in the mix, or frilly types may come from a particular part of Portugal.
Older Portuguese kale leaf
As for flowering, well it obviously does, or I would not have been given seed, but this plant didn't flower this year, its second year, when most of the other kales were flowering their heads off (including the walking stick kale, also known as Jersey kale). Another one that didn't flower very much however, was one that came to me as seed, via the Heritage Seed Library, labelled as 'tall kale'. It shares some characteristics with the Portuguese cabbage having large leaves with white midribs and veins and a similar height. But it is more tree-like than the Portuguese kale with heads of leaves arising from separate branches.
'Tall' kale leaves
At present at least, the leaves of the Portuguese kale all arise from about the same place at the top of the stout stem. As the plant grows from the crown it drops its lower leaves and so the bare portion of the stem gets longer.
Portuguese kale about to lose a lower leaf
I don't yet know how hardy this kale is. It survived last winter with ease but it was a mild winter. Some sources I've read suggest that it is not only very cold-hardy but more likely to be perennial in cold climates, whilst others suggest the opposite on both counts. Luckily it is easily propagated from cuttings (scroll halfway down this forum page to find some great photos of the kale growing in Portugal and how to propagate it). It occurs to me that even if it isn't reliably hardy in the UK, taking cuttings like this is a very easy way to have a perpetual supply of kale.
Portuguese kale is used to make a delicious soup, beloved of many Portuguese people, called caldo verde and described very lovingly in this delightful blog post by Joy Albright-Souzaby. I based my attempt on the recipe given there but, as we are vegetarians, I used vegetable stock and, instead of Portuguese linguiça (smoked pork sausage), a vegetarian 'sausage' made from lentils flavoured with lots of smoked paprika and garlic.
Refer to the recipe in the link above for exact instructions (to make about six portions I think) but basically I boiled the potatoes in the stock until they were almost tender and then added the sautéed onion and garlic with the (ideally!) very finely shredded cabbage and more water. The soup was seasoned and simmered for about half an hour.
I made the vegetarian 'sausage' by mixing cooked lentils with sautéed onion and garlic, breadcrumbs, egg, olive oil, smoked paprika, salt and pepper and forming patties with the mixture, coating them in flour and baking them at 180°C for about thirty minutes, turning them over halfway through the baking time. In the recipe the linguiça is cooked alongside the onions and garlic for a while and simmered with the soup but I thought the lentil patties might disintegrate in the soup and so added them to it just after it was put in the bowls.
Smoked paprika and lentil patties
The soup is often served with freshly grated Parmesan cheese to sprinkle over - I meant to serve some grated cheddar instead for the sake of economy but then forgot about serving cheese altogether.
The recipe said to eat the soup with crusty bread and glasses of red wine - so we did!
It was good.
N.B. I sell a range of perennial vegetable plants on my website.