Native lobelias

Underrated and in some cases endangered, this unique family of flowering native plants deserves wider recognition, and certainly more love from gardeners all over the country.

Did you know New Zealand has 13 distinct species of lobelia? The most familiar, Lobelia angulata is relatively easy to grow and makes a fine show (others in the family are a bit more difficult). Gardeners around the country all recognise the small bedding plant with flowers of dark blue, light blue, pink and white, and all colours in between. They are easily grown for summer displays.

But not all New Zealand lobelias would be familiar to the average home gardeners, and some species are downright rare. In fact several of our native lobelia are technically classified as At Risk or Declining.

Lobelia belong to the Campanula family, Campanulaceae. People will recognise this name for the common perennial campanula and wonder how lobelia looks like them. Well, the family is very cosmopolitan occurring throughout the world except Antarctica. Botanists created three sub-families, one of which is Lobelioideae which contains the genus Lobelia.

The genus Lobelia was formally described in 1753 by Carl Linnaeus in Species Plantarum (which lists every species of plant known at the time, classified into genera) and was named after the Flemish botanist Matthias de Lobel (1538–1616), a physician with an interest in plants who wrote a number of articles.

He was also the first botanist to recognise the difference between monocotyledons (such as grasses and lilies) and dicotyledons (flowering plants). The genus Lobelia is made up of 415 species of annual and perennial plants worldwide.

New Zealand lobelia are interesting in that of the 13, only three were originally classified as Lobelia while the others were put into a different genus, Pratia. Today, botanists recognise all of them are Lobelia.

New Zealand being an island nation has enabled lobelia to adapt to a variety of situations. We have one large leafy species (Lobelia physaloides), several ground crawling species and two alpine species which are completely different to each other. Several are specific to certain habitats and difficult to find as these habitats are shrinking due to land use change and browsing.

Species you may come across Lobelia angulata

Pānakenake is easily grown and can be found for sale in garden centres. It is a creeping plant which when established can create a thick mat of leaves and stems up to 10cm high in shady places. In full sun this reduces down to 1 or 2 cm high. It is used in some commercial landscapes as well as the home garden.

L. angulata is easily recognised when in full flower with its typical lobelia-like white flowers appearing on thin stalks above the foliage. It flowers for quite a long time during the summer and autumn, making a great show.

Following flowering, it produces large purplish berries which also can be attractive (though some forms are unisexual and will not produce fruit). In the wild, these fruit are even more interesting and attractive as usually the plant is quite flat to the ground showing off its fruit.

Surprisingly, I found it growing on a golf course (while at a stag do for my future son-in-law) and spent more time observing this than playing golf. On the mown fairways, these little starry lobelia flowers were popping up all over

Surprisingly, I found pānakenake (Lobelia angulata) growing on a golf course (while at a stag do for my future son-in-law) and spent more time observing this than playing golf.

the place especially in cooler, damper areas. Close inspection showed the plant was growing along the ground between the grass plants and sending up flowers just above grass height. It was thriving and making a great show.

I have also found it in the lawns of home gardeners doing exactly the same thing. So impressed, I have planted one in my own lawn to replicate this as lawns can be so boring. Mind you, I can’t now spray it for lawn weeds but who cares when the flowers are out.

Earlier this year, on visiting the West Coast at Moana, I noticed lobelia flowers growing in some rough grass and had a close look and thought they were a different species. Here were delicate, soft, thin creeping stems, with smaller, more rounded leaves and slightly smaller flowers.

Thinking it was different, I was able to get two or three pieces and have grown them at home. It has retained that delicate form in a pot and has so far not exhibited the toughness of the forms sold through garden centres.

It shows that even the same species can exhibit different forms based on habitat. It remains to be seen if it may become a new species when another review is completed.

Similar plants have been reported on Auckland’s west coast. It is called Lobelia ‘Woodhill’ or more particularly Lobelia aff. angulata where aff. means it is like L. angulata.

For ease of identification when not in flower, one needs to look at the leaves which should be rounded via a few angled corners (hence the angulata in its name).

If you are looking for this in nature, then it grows throughout the three main islands in damp situations anywhere from sea level to about 1300m.

Lobelia macrodon

As my friend and botanist Lawrie Metcalf wrote in his book on New Zealand native plants, this plant is a gem.

It is slower growing, perfectly flat to the ground with lovely bright green, shiny leaves and wonderful sweet smelling cream-coloured flowers. Not often available but well worth the effort to find a plant either in the wild or for sale. Specialist native plant nurseries may have it.

It never climbs over itself and seems to want to occupy new ground. Roots are produced at the nodes and find their way down into a rather firm but gritty moist soil with reasonable amount of sun.

The flowers are produced almost directly off the main stem. In bud, they look somewhat inflated with a bulbous look about the petals before they open. Upon opening you have to get on hands and knees to get you nose close enough to really smell the exquisite perfume they emit. Of course you can pick one to save the trouble of getting down to it but that means one less flower as it does not produce masses of flowers. (It also seems that the flowers once open are also delicious to small friends in my garden as I hardly ever see them getting old.)

The fruit is greenish-purple but never an attractive part of the plant.

If you are looking for this in the wild, you need to get into sub-alpine and alpine areas of the South Island in herb fields, rocky outcrops and scree margins, and similar areas.

Lobelia perpusilla

Exploring new areas of New Zealand is always a great joy and you never know what you may find unexpectedly. Having completed a round trip walk at The Pyramids near Dunedin, where there is interesting geology as well as a variety of plants, I wandered over to what looked like a volcanic cave and there covering the ground was a wonderful display of white flowers covering an area of about 100 square metres.

Once again, down on my knees I went to check it out. Yes lobelia flowers but with a slight bluish tinge to the white flowers. Flowers growing almost directly off the creeping stem and producing many, many flowers especially in this location. I have seen reports that suggest the North Island form may produce more flowers but it is certainly not the case at The Pyramids. The flowers also produce only a mild perfume.

It is easily distinguished from L. macrodon, as L. perpusilla is also flat growing but its leaves have a dimpled effect clearly shaped by strong veins in the leaves and it has hairs on the leaf.

Naturally, it can be found growing in damp coastal hollows through to similar conditions in the low flat damp tussock areas of New Zealand.

If you want masses of lobelia flowers growing flat to the ground, this may be the one.

Lobelia physaloides. Colensoa, Koru

Sticking with the coastal theme, Lobelia physaloides is a totally different plant found only in the northern parts of New Zealand from Te Paki in the north to near Whangārei in the south. Also known as colensoa or koru, it also occurs on Three Kings, Poor Knights, Hen (Taranga) and Rakitu Islands.

Its presence on Rakitu Islands suggests it was once more widespread.

I have seen it in cultivation in Wellington along a stream in the Botanic Gardens and under shelter in the Christchurch Botanic Gardens.

I found it in the wild at Maitai Beach above the high tide mark, in an area fenced from stock, on the Karikari Peninsula and growing in the shade of very large pōhutukawa trees. Unfortunately, it was not in flower when I was there.

It’s easy to mistake this plant for something else as it is unlike any other lobelia species in New Zealand. It is large

about 1m by 1m, with large palatable leaves meaning it survives well in places where browsing animals can’t easily get to it. It is declining on the mainland.

It looks a little shaggy in the wild but in cultivation with shelter, it is a wonderful plant with its large leaves, large long blue-violet flowers and purplish blue berries. The flowers are similar to the larger lobelias from overseas.

Growing in a cool damp place it survives well if given frost protection. Therefore as an understorey plant, it is well worth considering.

Lobelia roughii

From the coast to alpine screes, lobelia grow in many places but Lobelia roughii is hands down our weirdest lobelia and also a weird-looking alpine plant.

Growing on alpine scree slopes in the mountains of the South Island, it is easily recognised whether in flower or not.

I first came across it when exploring some shingle scree areas on Mount Hutt quite close to the ski field access road. The next year I went back and could not find any due to the moving nature of alpine screes.

It is a specialised plant of alpine scree areas and as such a plant that alpine plant experts might like to grow.

The leaves are fleshy, almost Ilex-like, dark green with orange tips on the leaf points. The plant itself is compact, with leaves providing a method of conserving water and providing partial shade to itself on sunny days on hot shingle screes.

Flowers are white or pale cream with a light sweet scent. Rather than growing it, people may visit the area to see this strange looking plant growing in the wild. Ski field access roads are great for those that want to access alpine areas without too much walking and climbing. Get permission first though.

Lobelia linnaeoides

This is a rather inconspicuous alpine plant except when in full flower with its delicate pink opening to white flowers held up to 10cm high on thin stems.

It will grow quite well in a home rock garden and will form a tight mat of green leaves with darker purplish colour underneath.

It is worth seeing in flower in the wild, and for that, note that it is a South Island alpine plant occurring from the Ashburton River south to northern Southland.

Our New Zealand lobelias are a great mixture and worth growing in gardens both public and private, and in some cases would make great commercial landscapes.

In the future, I hope we will see more of them included in the second stage planting of conservation projects as they are just as valuable as the many trees and shrubs that get planted.