Leafless Mistletoe
Botanical name: Korthalsella lindsayi
Synonyms: Viscum lindsayi, Heterixia lindsayi, Korthalsella lindsayi var. lindsayi
Common name(s): Leafless mistletoe, dwarf mistletoe, Lindsay’s mistletoe
About:
Korthalsella lindsayi is a remarkable tiny endemic New Zealand mistletoe that lives attached to the branches and twigs of other woody plants. Rather than producing conventional leaves, it forms dense clusters of flattened, fleshy green stem segments that perform photosynthesis.
Plants are usually only 3–5 cm long but can reach approximately 10 cm. The flattened, bead-like segments, minute flowers and tiny sticky fruits make this one of New Zealand’s more unusual native flowering plants.
Although dependent on a host plant for water and mineral nutrients, Korthalsella lindsayi contains chlorophyll and produces much of its own energy through photosynthesis. It parasitises a surprisingly wide variety of native trees, shrubs and vines and appears to have no single obligatory host species.
Natural habitat:
Coastal to subalpine forest and shrubland, although most frequently encountered in coastal and lowland environments.
It is particularly associated with lowland alluvial forest, coastal forest, forest margins and shrubland where suitable host plants occur.
Unlike a conventional terrestrial plant, its immediate habitat is the living branch or twig of its host. It establishes a specialised connection with the host’s vascular tissues from which it obtains water and dissolved nutrients.
Growing environment:
Host-dependent, Sun to Partial Shade & Sheltered conditions tolerant.
Growing requirements are primarily determined by the host species and the natural environment in which the mistletoe occurs. It can occupy relatively exposed as well as shaded situations depending on its host.
It cannot be treated as an ordinary garden shrub or groundcover because it must establish directly on a compatible living host.
Endemic distribution:
Endemic to New Zealand.
Present in the North and South Islands.
In the North Island it occurs from around Pureora southward through Hawke’s Bay, Wairarapa and Wellington, generally becoming more abundant toward the southern North Island.
It is widespread through the South Island and appears particularly frequent in eastern districts.
Height:
Usually 3–5 cm long, occasionally reaching approximately 10 cm.
Width:
Individual masses may spread to approximately 10 cm or more across a host branch as repeated branching creates dense clusters.
Flowering:
October–March.
The flowers are extremely small and inconspicuous, developing on narrow specialised flowering branches that form short terminal or lateral pseudo-spikes.
Because of their minute size and greenish colouring, flowers can easily be overlooked amongst the segmented stems.
Fruiting:
October–June, with fruit often particularly evident through summer.
The fruit is a tiny, fleshy, obovoid berry-like structure approximately 2 mm long.
It becomes sticky at maturity, an important adaptation allowing the seed to adhere to the bark of a potential host.
Uses:
• Native biodiversity conservation
• Ecological restoration where natural host populations occur
• Specialist botanical collections
• Mistletoe and host-parasite research
• Educational displays
• Conservation gardens containing established host species
• Supporting the ecological complexity of indigenous forest and shrubland
It is not suitable for conventional landscaping or general nursery cultivation.
Appearance:
Growth habit:
A minute, densely branched, leafless parasitic subshrub growing directly from the branches and twigs of its host.
Plants branch repeatedly at relatively broad angles, creating distinctive compact masses of flattened green segments.
The stems are somewhat succulent and often give the plant a curious chain-like or beaded appearance.
Leaves:
True functional foliage leaves are absent.
Instead, the green stem segments perform photosynthesis. Individual internodes are thick, strongly flattened and typically obovate to broadly spatula-shaped, approximately 5–12 mm long and 3–9 mm wide.
They are generally widest toward their upper portion before narrowing abruptly into a strongly constricted node.
A minute collar, approximately 0.5 mm long and sometimes finely toothed, surrounds the node.
Flowers:
Flowers are minute and borne on specialised flowering branches.
These branches are considerably narrower and less flattened than the ordinary vegetative segments and form short terminal or lateral pseudo-spikes, with terminal flowering branches sometimes occurring as pairs.
The flowers are sufficiently small and inconspicuous that a plant can easily appear flowerless without close inspection.
Fruit:
The fruit is small, fleshy and approximately 2 mm long.
At maturity it contains sticky material surrounding the seed. This allows the seed to adhere securely to bark following dispersal, providing the opportunity for a new mistletoe to establish on a suitable host branch.
Ecology:
Korthalsella lindsayi is a specialised stem parasite and an intriguing component of New Zealand forest ecology.
After a seed becomes attached to a suitable host branch, the developing mistletoe establishes a physiological connection with its host through a specialised structure known as a haustorium. This penetrates the host tissues and connects with its vascular system.
The mistletoe subsequently obtains water and mineral nutrients from its host while its green stems continue to photosynthesise.
It has been recorded parasitising a diverse range of woody plants, including species of Coprosma, Lophomyrtus, Melicope and Muehlenbeckia, among others. No single host preference appears to apply throughout its range, although regional host associations may occur.
Its sticky fruits and seeds have an unusual dispersal system involving ballistic projection and subsequent adhesion to vegetation. Animals may also contribute to dispersal.
Associated habitats:
Coastal forest, lowland alluvial forest, broadleaf forest, forest margins, shrubland, montane vegetation and occasionally subalpine communities.
Its associated plant community varies considerably because of its broad geographical and elevational range.
Suitable host plants are the critical component of its habitat, and populations can occur wherever compatible woody species and appropriate environmental conditions coincide.
How to grow:
Korthalsella lindsayi is extremely difficult to cultivate and should not be removed from wild populations.
Unlike an ordinary plant, it cannot simply be transplanted into soil. Successful establishment requires a viable seed to attach to a suitable living host and subsequently penetrate that host’s tissues.
For conservation cultivation, the most appropriate approach is therefore to maintain healthy potential host plants and attempt establishment using freshly mature seed under specialist conditions.
Wild plants and infected branches should be left undisturbed.
Propagation:
Propagation is difficult and specialised.
Fresh mature fruit provides the only practical starting point. The sticky seed must be placed directly onto a suitable young branch or twig of a compatible living host, mimicking natural dispersal.
Successful germination alone does not guarantee establishment; the developing seedling must form a functional haustorial connection with its host.
Conventional propagation techniques such as ordinary seed trays, cuttings, division or rooting pieces are inappropriate for this species.
Collection from natural populations should not be undertaken without appropriate conservation consideration or authorisation.
Cultural use:
No well-documented traditional Māori material use specific to Korthalsella lindsayi is widely recorded.
Its significance today lies particularly in its place within Aotearoa New Zealand’s distinctive indigenous flora and as an example of the highly specialised ecological relationships that have evolved within native forest communities.
Garden value:
This is primarily a conservation and botanical-interest species rather than a conventional garden plant.
For specialist native collections, however, an established Korthalsella lindsayi growing naturally on a host is exceptionally interesting. Its tiny flattened stems, unusual parasitic lifestyle and minute reproductive structures demonstrate an aspect of New Zealand plant diversity that can easily go unnoticed.
It is best appreciated and protected where it occurs naturally, or maintained within carefully managed conservation collections containing appropriate host plants.