Tree of the moment: Rewarewa

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A rewarewa flower unfurling beside a busy street in Tauranga. Just visible in the background are the old seed pods. Photo: Sandra Simpson

I spotted the rewarewa tree in Greerton’s shopping area a couple of years ago but had never been in the right place at the right time (with camera) to get a photo of the beautiful flowers – until now.

Sandwiched in tarmac between a small off-street carpark and the footpath it wouldn’t seem to be in ideal conditions but it’s apparently thriving and covered in racemes of intricate flowers just opening or waiting to open. I was once told that rewarewa flowers “are like candyfloss to possums”.

Knightia excelsa grows naturally throughout the North Island, but only in the Malborough Sounds in the South Island, according to the Tane’s Tree Trust website. Maori appreciated the flowers for their nectar, but didn’t use the attractive wood, which is usually pale with a reddish-brown fleck. Early settlers called it the bucket of water tree as it made useless firewood! Its more common name is New Zealand honeysuckle. Honey produced from the tree is said to be a beautiful deep reddish-amber colour with a rich, full bodied caramel-like taste.

The trees are a colonising species in the wild and grow in a conical shape – up to 30m tall but with only a 1m diameter trunk – and have tough, leathery leaves. Lawrie Metcalf writes in his 2011 book The Cultivation of NZ Trees and Shrubs (Raupo) that rewarewa will grow in sun or shade, although very dry conditions will make growth slower.

“The flowers secrete copious quantities of nectar at their bases, to which tui and bellbirds are attracted. In fact, the birds can often be seen investigating the state of the flowers long before they are ready to open. In their desire for the nectar the birds are dusted with pollen, which they transfer from the younger open flowers to the receptive stigmas of the older flowers.”

The tree is a member of the Protea family and distantly related to the Banksias of Australia.

In his 1884 book, Medical Botany of New Zealand, P J O’Carroll noted that the inner part of the bark was bandaged on to wounds and he had seen several wounds healed in a surprisingly short space of time. PME Williams in Te Rongoa Maori (Raupo, 2008) notes that the inner bark was applied in its raw state by bushmen to stem the bloodflow from cuts, and the bark was also used as a bandage. Researchers in 1987 reported that the bark contains beta-sitosterol, a major component of an American proprietary drug used to lower blood cholesterol levels.

Knightia excelsa was first collected at Tolaga Bay in 1769 by Daniel Solander during the first voyage of James Cook.

Our native plants: Whau

Entelea arborescens is a large shrub or small tree, the only one in its genus, and is part of the mallow family, which includes hibiscus, lacebarks and ribbon wood. The trunks of some members have tough fibres as a layer under the bark and these fibres have been used in many countries to make ropes, hats, mats and fishing nets, with the most important fibre in this family being the cotton plant.

Whau has large, soft leaves and is found where it doesn’t get browsed, which in my case meant the base track of Mauao (Mt Maunganui), although I’d seen the spiky, brown seedpods before and wondered what the plant might be. This particular day my attention was caught by the pretty, white flowers on a plant.

The flowers of whau have attractive crinkled petals and resemble a single rose. Photo: Sandra Simpson, taken on Mauao base track

Years ago I’d been told by someone who made wooden jewellery that not only was whau a very light wood, it also had an interesting green tinge to it. In fact, the wood is so light it was used by Maori as fishing floats, while long fibres from the trunk were used as fishing lines. (I’ve read that, when dry, whau in comparison to cork is no more than half the weight.)

The Meaning of Trees website entry says seasoned trunks were also lashed together with supplejack to construct small rafts for hunting crayfish and the plant was of such value to Māori that in some places it was actively cultivated. The Māori name of Auckland’s dormant volcano Mt Eden is Maungawhau (Mountain of the Whau Tree) so its slopes would likely once have been covered in whau, providing a constant supply of fishing material.

The NZ Plant Conservation Network entry says whau is found on Three Kings Islands, North (including Little and Great Barrier Islands) and South Islands. In the North Island, whau is locally common from Te Paki to about Kawhia and Mahia Peninsula, south of there it is known from a few sites in the eastern Wairarapa, at Paekakariki and Wellington. In the South Island it is confined to the Golden Bay area of northwest Nelson.

“Recent field work gathering samples for a Marsden study into the possible past use of whau by Maori indicates it is much less common in the North Island than it once was. Browsing pressure from cattle, goats and horses, clearance of coastal scrub of housing and the spread of invasive woody shrubs and trees into many northern coastal areas may be threatening some populations.”

The tree’s spiky seedpods, pictured at Zealandia in Wellington. Photo: Sandra Simpson

This pioneer species tree is short-lived, surviving for between 10 and 15 years, although easily grows from seed and cuttings. Laurie Metcalfe in The Cultivation of NZ Trees and Shrubs (Raupo, 2011) says the tree grows rapidly, is frost tender and once established can endure dry spells.

PME Williams is his book Te Rongoa Maori (Raupo, 1996) reports that leaves, heated in water, were made into a poultice for treating wounds and sores.

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.”