Clematis

New Zealand contains many beautiful (and beautifully-scented) species of Clematis, a genus well represented throughout the world. The New Zealand Clematis species are so distinct that they have been ranked (by the world’s leading Clematis expert, Magnus Johnson) as a separate section of the genus.

The flowers of all species are either white, greenish-yellow or yellow, a colour range that is representative of many New Zealand plants. This is probably related to the composition of New Zealand’s insect flora – New Zealand’s insect pollinators are considered to be less specialised than in other lands.

Clematis spp. ‘climb’ through a physiological function called haptotropism, by which the tendrils of the plant bend towards an external stimulus upon contact with it. This happens over the course of minutes, and further bending occurs, as the first point of contact ensures further contact with the outside stimulus, resulting in the characteristic coiling of the climber’s tendrils.

With an unusual appearance that would challenge most people’s perceptions of what a Clematis looks like, C. afoliata is probably the strangest of New Zealand’s nine Clematis species (although C. quadribracteolata gives it a good run for its money). One need look no further than the common name of this singular plant for the reason. The leafless clematis forms mounds of sprawling rush-like stems, that are made to look even more unusual when the plants erupt into flower in spring.

C. afoliata is a plant of open ecologies, such as grassland, scrubland and rocky areas. Its natural range follows the dry eastern flanks of the lower North Island (Wairarapa, Wellington and, historically, Hawkes bay) and South Island (where it is most prevalent within Marlborough and Canterbury).

It was initially described off specimens from Puketapu hill, near Napier, where it has been extinct for a very long time. Considering this historical record, we planted a significant number of leafless clematis in the lower reaches of the eastern flower border at our Te Mata garden.

Although leafless plants may not stir the hearts of some gardeners, this is a very beautiful and useful plant that should be more widely grown. When viewed flowering en masse, C. afoliata is a breathtaking sight, whilst its winding bright green stems have a peculiar appeal (especially when viewed in association with differing growth or leaf forms). It is particularly useful on account of its resilience to dry, open conditions, especially in areas where extreme insolation and summer-dry conditions place great demands on plant growth.

As a final note, even though Clematis afoliata derives from harsh habitats, a good tip (which applies to many plants from similar situations) is to plant specimens adjacent to rocks (preferably dug into the ground), from which they receive some level of respite and moisture.

The pale greenish-cream flowers of C. cunninghamii can be encountered within the interior and fringes of northern forests from Hawkes Bay north, in late spring and early summer. This species was previously known as C. parviflora, a name that means small-flowered in Latin; although its fragrant flowers are not actually that small (within the context of New Zealand’s flora), especially as they are borne in reasonably large inflorescences¹.

Due to the narrowness of the tepals², the flowers’ appearance is often more strongly marked by the sexual parts of the flower (the stamens or pistils, depending on whether one is looking at a male or female plant). This gives the flowers a somewhat frothy look, as shown in the largest flower in the photo below.

Clematis cunninghamii should be planted in the shade of its support plants, in conditions that are reasonably free-draining, but do not dry out too much. I have viewed it growing in relatively dense shade on Mt Manaia near Whangarei, and in a similar aspect within coastal forest at Wenderholm Park, to the north of Auckland. Its capacity to flower beneath the forest canopy is worth noting, as it may be of particular use for providing flowering interest beneath larger trees – many other native Clematis require a comparatively open aspect to flower.

C. cunninghamii is named after an English botanist, Allan Cunningham, who reached our shores (in 1826) as a collector for Kew Gardens. Cunningham spent his time within New Zealand in the Far North, where he made many contributions towards the knowledge of the New Zealand flora, including discovering the beautiful, highly-scented genus, Alseuosmia (and collecting this species for the first time from Whangaroa).

This scented Clematis species presents masses of small, buttery yellow flowers in late spring. It is scarcely grown, but deserves to be more widely cultivated, although at times the difficulty involved in procuring plants can be inhibitive to wider use. Its species name is very misleading, as this plant is in no way foetid; a colleague with whom I observed this plant described the scent as similar to feijoa.

It grows in open situations and on forest margins throughout lowland forests of the North and South Islands. It is a smaller-growing plant than Clematis paniculata, climbing to the tops of small trees, or scrambling through filiramulate (otherwise known as divaricate) shrubs, in the areas where it occurs. It is perfectly capable of growing in modified environments, like roadsides, such as on the Napier-Taupo road (Where I observed it was growing through weedy patches of blackberry) or on the western side of Lake Wanaka (where it forms huge garlands over both native and exotic trees).

Within the garden, C. foetida (like several other native species) should be given a position where its base can be in shade, but the head of the plant can climb to the light. Bearing this in mind, shrubs or small trees between 2.5 and 5m tall make ideal supports.

Clematis forsteri often grows through filiramulate shrubs on our rocky coastline, from whom it receives the shelter and structural support that it requires for growth. It is found in lowland forest (particularly in forest margins) in the central-southern North Island and northern reaches of the South Island. C. forsteri is often found in very difficult conditions within nature, making it one of the best species for gardens in the northern and central parts of New Zealand. I have viewed a particularly good population, growing on cliffs in coastal bush in the spectacular limestone landscapes of the south side of Kawhia harbour. In several spots, the plants were growing in very shallow, sun-drenched soil, similar to the conditions found in many urban gardens.

The flowers (which can vary in colour from a greenish-cream to a pale yellow, depending on the propagation source) appear in October and November, and are borne on the previous year’s wood. The scented flowers are followed with fluffy seedheads. It can grow to 3 – 3.5m, although it is generally more compact in native coastal vegetation. It, like all New Zealand Clematis spp., is dioecious, but (atypically) there are only slight differences in the size and fineness of male and female flowers.

It derives its name from the botanist Johannes Foerster, who was an early European visitor to our shores, accompanying Captain Cook on one of his voyages to New Zealand. This species of Clematis is becoming increasingly known overseas with Clematis enthusiasts, but is almost unknown in New Zealand.

It should be noted here that the plant formerly known as Clematis hookeriana is now recognised as being part of the variable C. forsteri species. That form is a particularly worthwhile plant for inclusion in gardens, on account of its resilience to wind, drought and other adverse conditions. This is due to its natural habitat, the shorelines of Cook Strait (such as at Turakirae Head, where the specimen shown above was growing), where it is subjected to extreme coastal conditions. It has quite green, small flowers, with more finely dissected foliage than other forms of C. forsteri.

Like others of our native Clematis species that live in the shadow of C. paniculata (in gardening terms), Clematis marata is a very fine plant that merits greater attention. This delicate species is especially deserving of further use for its tough constitution, as well as the fact that it occurs in areas of the country that other species do not extend to. C. marata displays its pretty greenish, scented flowers in late spring within dry habitats of the eastern South Island, often scrambling through divaricate shrubs that are well-sized to accommodate its diminutive size (it normally reaches between 80cm and 1.5m high).

I have observed this species in a number of extremely difficult habitats, including the margins of a highly modified river near Lake Tekapo, in scrub on a sloping moraine on the Two Thumb Range in the Mackenzie Basin, and on cliffs near Lake Aviemore. One particularly beautiful natural combination was to be seen in the latter location, where the fresh green of C. marata‘s foliage seemed to float above the beautiful silvery foliage of an unusual member of the daisy family, Helichrysum intermedium.

C. marata often grows in the same habitats as its relative, C. quadribracteolata; the latter bearing more inconspicuous purplish-brown flowers. Although somewhat similar, these species are reasonably easy to tell apart, based on the more verdant, substantial (and open) appearance of C. marata‘s foliage. Both of these species are distinct from other New Zealand Clematis, by always having four tepals².

Puawhananga (‘flower of the skies’), the most popular of our native Clematis species, adorns the upper layer of our native bush, trailing up forest trees and providing a remarkable spring display of white flowers. It is extremely free-flowering and will flower relatively soon after propagation, making it a valuable ornamental plant.

It is endemic to New Zealand (i.e. found nowhere else in the world), as are all our species of Clematis. The New Zealand species of Clematis are dioecious (bearing male and female organs on separate plants), which is significant for garden usage as the male plants generally bear larger, finer flowers. Most horticultural forms are selected accordingly (for the bigger male blooms), but gardeners wishing to establish meaningful populations of this plant should select seed-grown plants (so that there is a chance of viable seeding).

C. paniculata must be treated as a true forest plant in cultivation, and given conditions similar to its natural habitat. Like many other Clematis spp., it requires a cool root run, plenty of humus around its base and consistent moisture. Puawhananga should be trained up a medium-sized to tall tree to achieve the best effect.

It was traditionally a harbinger of spring to Maori, for whom it was also connected with the harvest of eels, a spring event. Puawhananga and whauwhaupaku (Pseudopanax arboreus) were the children of Rehua (the star Antares) and Puanga (the star Rigel in Orion), and their task was to announce the coming warmth of summer – which Rehua (who also represented the forest itself) represented. It flowers from August to November, and is found throughout New Zealand in lowland and lower montane forests. It was first collected on Cook’s second voyage, by the German botanist Johannes Foerster.