In The Hills In The Hills 2015-12

Aristotelia serrata < Species index > Asplenium flabellifolium

This article was first published in the Tararua Tramper Volume 87, no 11, December 2015

December in the hills with Barbara Mitcalfe and Chris Horne

Asplenium bulbiferum, Manamana, Hen and chickens; Mother fern

In last month's article we described Asplenium flaccidum. This month's plant choice is another common member of the asplenium genus: Asplenium bulbiferum. Its Mēori name, 'manamana', is probably an emphatically complimentary 'tag name' derived from the word 'mana' which means prestige* (see Uses) or dignity. 'Bulbiferum' means 'bearing bulbs', In the bush you have probably often seen manamana's large handsome fronds carrying tiny young fernlets called bulbils on their top surface 'like a brood of chickens'. (See image). Sometimes the whole frond falls off or is knocked off and all the bulbils get 'planted' at once!

Asplenium bulbiferum fronds showing bulbils Photo: Jeremy Rolfe

Reproduction

Bubils are a most unusual method of fern reproduction in NZ. The bulbils on top of the manamana frond are complete young fern plants which have grown there directly out of the cells on the frond surface. When the bulbils have sprouted one or two tiny fronds of their own they will detach and land on the soil, sprout roots, and live a life completely separate from the parent plant.

Asplenium bulbiferum is also unusual in that it has two ways of reproduction, one as above, non-sexual via bulbils, and the other, like other ferns, sexual. The sexual method of reproduction in ferns is cyclic and complex, involving spores and both sexual and non-sexual phases. Spores are single-celled reproductive organs, but neither male nor female. When mature, spores fall to the ground or are further distributed by wind. In damp conditions, on the ground, each spore may then develop into what is called a prothallus. Though only about the size of ½ a fingernail, each prothallus develops two separate sets of sexual organs, one producing eggs and the other sperm. Fertilisation between them produces tiny new fern plants which grow just like any other fern plant, thus completing the cycle.

Form and size

Manamana is terrestrial, with dark green, elliptic fronds ascending from the rhizome in a graceful curve, and extending for 12 – 120 cm x 4 – 50 cm. (shorter and broader than last month's Asplenium flaccidum fronds). The stems are brown at the base and green further up. The fronds' slim, tapering segments can be up to 35 cm long and are dissected 2 or 3 times further into smaller parts, making an intricate, elegant pattern. The sori on the back of each are typically neatly arranged at c. 45 degrees to the midrib.

Distribution

Asplenium bulbiferum is found in lowland and montane forest in the North, South, Rakiura / Stewart, Rekohu / Chatham and Antipodes islands and also in Australia. If you're tramping in Central Otago or the drier parts of South Canterbury you will not be likely to see it there, as it prefers moister environments.

Uses

As its Māori name implies, manamana had many ceremonial* uses such as a placatory offering to Tāne when a tree had to be felled for waka-making; or as soft swaddling for a new-born baby. Young manamana shoots were a popular culinary vegetable wrapped round fish or birds in the hāngi and mature fronds were sometimes even woven into clothing. Along with a number of other indigenous plant species manamana was sometimes soaked and used as a rongoā wash to bathe painful cutaneous conditions.

See also

Category

Botany 2015

In The Hills 2015-11 < Index chronological > In The Hills 2016-02