Three Kings Davallia

Botanical name: Davallia tasmanii subsp. tasmanii
Synonyms: Davallia tasmanii
Common name(s): Three Kings Davallia, Davallia

About:
Three Kings Davallia is a distinctive creeping fern endemic to Manawatāwhi / Three Kings Islands. It forms spreading colonies from long, scaly rhizomes and produces dark green to yellow-green, leathery fronds with a broadly triangular outline. It grows both on the ground and as a low epiphyte, tolerating conditions ranging from full sun to deep shade within its isolated island habitat.

Natural habitat:
Coastal island forest, shaded ground, rocky banks, fallen logs, low tree trunks and branches. It grows terrestrially or as a low epiphyte in both exposed and heavily shaded positions.

Growing environment:
Prefers a warm, frost-free position with excellent drainage. It grows well in full sun or partial shade but should be protected from severe cold and competition from vigorous surrounding plants.

Endemic distribution:
Endemic to New Zealand. Confined to Manawatāwhi / Three Kings Islands, including Oromaki / North East Island, Manawatāwhi / Great Island, Moekawa / South West Island, Ōhau / West Island, Arbutus Rock and Hinemoa Rock.

Height:
15–40 cm

Width:
Spreads to 1 m or more by creeping rhizomes.

Flowering:
N/A – ferns do not flower.

Fruiting:
Spores may be produced on mature fertile fronds.

Uses:
• Native fern collections
• Container growing
• Warm shaded rock gardens
• Epiphytic displays
• Coastal fern gardens
• Conservation collections

Appearance:
Growth habit:
A creeping terrestrial or low epiphytic fern with long, widely spreading and branching rhizomes. The rhizomes root at intervals and gradually form loose colonies over soil, bark, logs and rocks.

Rhizomes:
Rhizomes are 2–8 mm thick and densely covered in pale orange-brown to yellow-brown scales when young. The scales gradually shed as the rhizomes age.

Fronds:
Fronds are broadly triangular to five-angled, dark green to yellow-green and leathery in texture. They are divided three or more times into finely cut segments and may reach about 28 cm across. The lowest primary pinnae are noticeably larger than those above.

Stipes:
Frond stalks are stout, wiry and almost black, becoming glabrous except for scales near the base.

Flowers:
No flowers are produced. This species reproduces through spores.

Fruit:
No fruit is produced. Spores develop within sori on the lower surfaces of fertile frond segments.

Sori:
The sori are contained within distinctive pouch-like indusia positioned near the margins of the frond segments. This feature makes the species relatively easy to identify when fertile.

Ecology:
The creeping rhizomes help the fern spread across forest floors, fallen wood and low branches. Its dense foliage provides shelter for small invertebrates and contributes to the humid ground-layer vegetation of the Three Kings Islands.

Associated habitats:
Coastal forest, island scrub, rocky ground, fallen logs, shaded banks, tree bases and low epiphytic habitats.

How to grow:
Grow in a warm, sheltered position in free-draining soil or a coarse bark-based potting medium. It performs particularly well in containers and tolerates becoming root-bound. Avoid disturbing established rhizomes and protect the plant from frost and aggressive neighbouring plants.

Propagation:
Propagated from fresh spores or rooted rhizome sections. Rhizome pieces usually establish successfully but may be slow to begin active growth. Spores are also viable but generally slow to produce mature plants.

Cultural use:
There are no widely documented traditional Māori uses for this restricted island fern, but it is an important component of the unique flora of Manawatāwhi / Three Kings Islands.

Garden value:
A highly ornamental fern valued for its glossy divided fronds, dark wiry stalks and creeping rhizomes. It is especially suitable for pots, ferneries and warm coastal gardens where its unusual form and rarity can be appreciated. Because of its frost sensitivity and dislike of root disturbance, it performs best in a protected position