Tree of the moment: Puriri

Although puriri trees (Vitex luscens) can flower and fruit off and on all year round, winter is the start of the main flowering season, and while visiting Te Puna Quarry Park at the weekend I finally got my first decent shots of puriri flowers – relative to the size of the tree the flowers are small and often hidden underneath the spreading canopy.

The tree is naturally found in roughly the top-third of the North Island. Its pretty flowers provide nectar for birds, while the fruit is an important food source too. The birds return the favour by spreading puriri seed with a helpful little dollop of fertiliser to start them off.

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Puriri flowers. Photo: Sandra Simpson

Lawrie Metcalfe (The Cultivation of NZ Trees and Shrubs, 2011) calls the puriri a “large, handsome tree” and says it grows rapidly when young to a mature height of 12-20m or more. Young trees are frost tender. In Tauranga we have an avenue of mature puriri trees outside the Domain on Cameron Rd, where they don’t seem to mind vehicles being parked on their roots day in and day out!

Alison Evans in New Zealand in Flower (1987) notes that puriri are distantly related to the teak trees of Burma and Southeast Asia, and have one of the longest flowering periods of any native plant.

European settlers used the hardwood for fence posts, railway sleepers, house piles, bridge building and furniture (the veneers have a walnut-like finish), while Maori used the timber for garden tools and weapons. The timber, “very hard, dense and heavy and of great strength” (Metcalfe), is no longer used commercially. The green puriri moth (Aenetus virescens) tunnels through the tree causing much damage, although I’ve seen a magnificent table top that made a feature of the moth’s handiwork. See an unusual cabinet made from puriri here, along with some interesting information about the tree, including that it was traditionally used for eel traps because it sank and that the bark makes a yellow dye.

In the charming small book, Te Rongoa Maori (Maori Medicine, 1996), author PME Williams says the liquor from boiling leaves was used to relieve sprains, backache and ulcers, and he had also heard of an infusion of leaves being taken as a drink to relieve kidney complaints.

Puriri were also used as burial trees by Maori and there is a venerable example, Taketakerau, at Hukutaia Domain near Opotiki in the eastern Bay of Plenty. The Meaning of Trees website offers an age of about 2000 years old, and says: “After the death of a chief or person of high mana, the body would be adorned with a coronet of puriri leaves, and washed with an infusion of the leaves and water.” The website is well worth a visit.

Part of the tree known as Taketakerau in Hukutaia Domain. Photo: Sandra Simpson

A sign by the tree says: “The bones of the distinguished dead some years after burial, were with much ritual, including on occasion the sacrifice of slaves, dug up, scraped, painted with oxide of iron and deposited in a cave or hollow tree where they could not be found and put to base purposes by tribal enemies.

“A tree such as this was highly tapu [taboo] and any desecration of such tapu was a deadly matter and an affront to the tribal atua (ancestral gods). The offender’s death would surely follow.”

Our native plants: Hibiscus trionum

I came across this little sweetie in an Omokoroa garden several years ago and was surprised to learn it was a “native hibiscus”  as I always imagine hibiscus as large, tropical shrubs, not front-of-the-border temperate zone plants.

Hibiscus trionum. Photo: Sandra Simpson

It’s generally classified as an annual, although in some places may be a two-year plant.

“Although rare in the wild, it naturalises freely from seeds in warm sites throughout the country, even in the southern South Island,” according to Alison Evans in New Zealand in Flower (get a copy from a book fair near you.)

“There is some evidence that Hibiscus trionum may have been introduced to New Zealand by Maori who used the leaves for cleaning hands and may have cultivated it for this purpose and for its attractive flowers.”

Fiona Eadie, in her book 100 Best Native Plants for New Zealand Gardens, reports that there are two very similar types of H. trionum in the country – one native (and which also occurs in Australia) and one that was introduced by man and has naturalised.

The difference, she says, is that the latter has more finely dissected leaves and an almost maroon centre, so I think I’m right is saying that the one pictured here is the true native … or am I? Keep reading.

Flowering is from late spring into autumn and the plant typically forms a small bush about 50cm high. It can tolerate very dry conditions which may even encourage flowering and doesn’t mind coastal winds – but it doesn’t care for very wet positions and frosts. It sets seed readily. Unfortunately, the flowers are no good for picking as they wilt immediately but the seed heads are liked by floral artists.

However, since the two books I’ve referenced were published (1987 and 2008 respectively) there has been a bit of a rethink on the “native” status of H. trionum, something I was alerted to by a recent post of Abbie Jury’s.

Shirley Stuart, curator of the native plants collection at the Dunedin Botanic Garden, has decided to treat H. trionum it as a “non-indigenous fully naturalised native” after doubts about its origins were raised.

The Oratia Native Plant Nursery website says of Hibiscus richardsonii: “Previously known as Hibiscus trionum this yellow-flowered Mercury Islands form is now recognised as the true native species.” Read a full profile of H. richardsonii which is now accorded the name “puarangi”  previously given to H. trionum and which you’ll see is missing that dark centre.

Native or not, H. trionum is a pretty little thing that grows well and should be appreciated on its merits, not where it hails from.