Thursday, August 4, 2011

New Zealand: A Subalpine Stroll

I first visited New Zealand in 1974, on my way home after two years working on my doctoral thesis in Australia. Since then, with one thing and another, I had never been back to either country. This year, though, Eileen (who had been to New Zealand in 2004) proposed that we vary our annual trip to Malaysia by routing ourselves through both, combining visits to Malaysian friends who had emigrated southwards with a chance for me to see, again, a natural world I have long loved, and long missed.

We had planned to arrive in Auckland on March 1st, and fly the next day to Christchurch for a stay of several days. The mammoth earthquake at the end of February changed all that. We decided instead to head out from Christchurch after only a single night, and cross Arthur's Pass to the wild West Coast of the South Island and Eileen's ornithologist friend Kerry-Jayne Wilson.

My plan, on crossing Arthur's Pass, was to walk the Otira Valley trail to one of the few remaining "easy" sites for the increasingly rare Rockwren (Xenicus gilviventris). This is one of the two surviving members the Acanthisittidae, an ancient relic that is New Zealand's most distinctive songbird lineage.

As it turned out, the wrens failed to appear and the "walk" to their rock scree habitat turned out to be more of a scramble than a stroll.

No matter (well, almost no matter). The climb to the scree was worth it botanically if not ornithologically. New Zealand has a rich and unusual subalpine flora, and the Otira Valley is as good a place as any to get on close terms with it.

I am a zoologist, not a botanist. Fortunately, later in our trip I was able to run my photographic sampling of the plants along the trail by a very genuine botanist indeed, Hugh Wilson (you'll meet him in a later posting). He avoids the internet, so I can cheerfully blame him for any misidentifications.

There aren't many trees in the valley, but down near the bottom of the trail we found this Bog Pine (Halocarpus bidwilli) - not a pine, but  a member of the southern hemisphere conifer family Podocarpaceae, native to New Zealand. According to, it is named for John C. Bidwill, an alpine plant fancier who collected in New Zealand in 1839 and 1848.

The bright red berry in this photograph is Pentachondra pumila, an alpine member of the Australasian heather family (Epacridaceae).  What I didn't know until Hugh Wilson spotted it was that the really interesting plant in the photo is the scruffy-looking specimen creeping in from the left margin. It may look like a sort of badly-groomed moss, but it actually is Pygmy Pine or Mountain Rimu (Lepidothamnus taxifolius, Podocarpaceae), the world's smallest conifer.

These peculiar and attractive seed heads belong to Acaena inermis, a member of the rose family (Rosaceae). Acaena is a genus of 50 species, mostly in South America but with 19 native to New Zealand.  Many of them have barbed seeds (presumably evolved to catch the feathers of passing moas?), but not this one.

This extremely attractive plant is Anisotome pilifera, a member of the carrot family (Apiaceae [or, if you're old-fashioned, Umbelliferae]).  The genus Anisotome is endemic to New Zealand, with some sixteen species.  The grass in the background is Bristle Tussock (Rytidosperma setifolia).

Tussock grasses are a feature of the alpine and subantarctic regions of the southern hemisphere.  This one is Broad-leaved Snow Tussock (Chionochloa flavescens).  Also crowding into the shot are Phormium cooki (the blade-shaped green leaves on the right), Dracophyllum longifolium (the tall spindly stuff at the back) and Celmisia semicordata (the silvery plant at the lower left).

The Snow Lily (Astelia nivicola) is one of the more robust plants along the trail, and its berries are certainly striking. Astelia and its several dozen southern hemisphere relatives (in the Pacific, the Falklands and the Mascarenes) have recently been placed in their own family, the Asteliaceae.

Mutton-bird Scrub (Brachyglottis rotundifolia) is a daisy-like shrub (Asteraceae or Compositae).  The small-leaved plant clustering at the bottom of the upper photograph is Scarlet Snowberry (Gaultheria crassa - see below).

Celmisia is one of the most striking genera of New Zealand alpine plants - large, impressive daisy relatives with stiff, hairy leaves and, in autumn, crisp, dry flower heads.  Most of the seventy species are found only in New Zealand.  This one is Celmisia semicordata, the Mountain Daisy, also called Cotton Plant or, in Maori, Tikimu. It is endemic to lower alpine and subalpine areas in the South Island.

This is a more widespread mountain species, the Cotton Daisy (Celmisia spectabilis). The long, thin stems to its right, topped with a corona of stiff green leaves, belong to Hebe subalpina, one of about 100 species of Hebe (Scrophulariaceae) in New Zealand.

There is quite a range of size and shape among the Hebe species in New Zealand.  This is Boxwood Hebe or Mountain Box (Hebe odora).

Yet another Celmisia - Armstrong Daisy (Celmisia armstrongi).  The large, rather coarse-leaved fern at the right margin is Mountain Kiokio (Blechnum montanum).

Here is Blechnum montanum again, this time on its own.

Alpine Hard-Fern may not look very much like the previous plant, but it is a Blechnum nonetheless: Blechnum penna-marina.

I have a particular fondness for clubmosses - I don't know why; perhaps because they are such ancient plants, and I like to imagine what it must have been like to wander through a forest of tree-sized specimens back in the days of the Coal Age.  This is Mountain or Alpine Clubmoss (Lycopodium fastigiatum), a species also found in Australia, surrounded by tufts of Poa grasses.

One of the lovely things about alpine plants is the way mats of several species can clump together, vying for attention. Here, a tangle of Creeping Clubmoss (Lycopodium scariosum) pushes its way through a patch of broad-leaved Celmisia discolor and the needles of Dracophyllum uniflorum.

March is autumn in New Zealand.  Though there isn't much in flower, mushrooms are out, and a few, like these little orange members of (probably) the genus Cantharellula (Tricholomataceae), provide a welcome splash of colour.

In contrast to the raft of New Zealand endemics growing in the valley, Map Lichen (Rhizocarpon geographicum) is about as cosmopolitan as a land organism (or, since lichens are symbiotic combinations of a fungus and an alga, a pair of organisms) can get.  It ranges from Siberia and northern Canada to the fringes of the Antarctic continent.  In 2005, examples were even launched into space aboard a Soyuz rocket as part of a survival experiment.  After sixteen days of total vacuum, gamma rays and ultraviolet radiation, they were returned to Earth where they appeared none the worse for wear.  Notice, by the way, the ring of black spores surrounding each greenish patch.

I confess I was surprised when Hugh Wilson identified this plant as a member of the genus Epilobium (Onagreaceae) (specifically as Epilobium glabellum, the Smooth Spike-Primrose or New Zealand Willow-Herb, the last name a bit misleading as the species is also found in Australia).  It certainly did not remind me of our own Epilobiums back in Canada, which we call fireweeds because they sprout quickly after a fire.  I suppose this is further proof that Hugh is a botanist, and that I am not.

I wish that this South Island Mountain Foxglove (Ourisia macrocarpa, Plantaginaceae) had been in flower, as its flowers - at least based on photographs - seem extremely attractive (and only vaguely like the flowers of its somewhat distant relative the garden foxglove (Digitalis purpurea)).  Ourisia has an interesting distribution: 12 species in New Zealand, one in Tasmania, and a further 15 in the Andes of South America, where the genus apparently originated.

Scarlet Snowberry (Gaultheria crassa, Ericaceae) has red berries, but here it  is the leaves that are providing a bit of autumn colour.  Gaultheria, it turns out, is named for a Canadian botanist, one Jean François Gauthier (1708-1756), and I am familiar with the snowberry's better-known Canadian relative, Wintergreen (Gautheria procumbens) - so this plant was, in a way, a touch of home.

The little plant with the rosettes of greyish-green leaves is South Island Edelweiss (Leucogenes grandiceps, Asteraceae), a relative of the Rogers-and-Hammerstein Edelweiss (Leontopodium alpinum) of Europe.

These unusual parasol-shaped leaves (you can see them in the lower right of the lower photograph) belong to perhaps the most celebrated of the New Zealand alpines, the Mount Cook Lily (Ranunculus lyallii) - not a lily, but the largest buttercup in the world. I would love to see this species in flower one day!

You will have gathered by now that our visit was hardly in the height of the flowering season.  There were, however, a few exceptions: this is one of them, a New Zealand Bluebell (Wahlenbergia albomarginata, Campanulaceae).

The only plant really flowering in abundance was Common New Zealand Gentian (Gentianella bellidifolia). Those of you used to gentians in other parts of the world may be wondering about this one - why isn't it cup-shaped, and why isn't it dazzlingly blue as so many gentians are?  The questions become more interesting when you learn that all of New Zealand's thirty-odd gentian species have white flowers, as do most of its other showy flowering alpine plants.

Why are New Zealand's alpine flowers mostly white? Botanists, of course, have asked that question too.  The answer seems too be tied, as is so much that is strange about New Zealand's biology, to the islands' long history of isolation.  Colour in flowers is not for our eyes, but for the eyes of pollinators.  In other alpine regions, the pollinators are mostly long-tongued bees with excellent colour vision and a fondness for blue - but not in New Zealand, where native bees of the right sort are missing and the flies and moths that do the job instead aren't particular about colour.  No bees, no blue.

Animal life was notably scarce on the trail (aside from fellow hikers).  This golden hunter (Sphictostethus nitidus) is an endemic member of the family Pompiliidae, a group of wasps that feed their young by providing them with paralyzed spiders.

There are only a few species of native butterfly in New Zealand, but even these few can create identification problems. This is one of the coppers, a quite difficult group. It appears to be a Boulder Copper (Lycaena (Boldenaria) boldenarum), the species you might expect in thus sort of country. The veins on the hindwing of the more widespread Common Copper (Lycaena salustius), instead of being marked with a solid dark streak as here, have a thin black line running along each side.

After a long hoof to the top of the trail, I was greeted by an expanse of rocky scree decorated with immense boulders. All I had to do now was spot a tiny brownish bird about the size of (and with much of the behaviour of) an extremely small mouse, and the Rockwren would be mine. Well, I didn't. Anyway, as Eileen's photograph shows, it's hard enough to see me in there, and I'm a lot bigger than your average Rockwren. Oh, well... at least it is nice to know that there are still reasonably accessible places where this tiny and ancient bird is hanging on. Long may it remain so!