BLACK TREE FERN Mamacu cyathea medullaris
Sphaeropteris medullaris, synonym Cyathea medullaris, commonly known as mamaku or black tree fern, is a large tree fern up to 20 m tall. The trunk is black and covered with distinctive hexagonal stipe bases. The fronds may be up to 5 m long, and arch upwards from the crown. Dead fronds are shed except in very young plants. The primary pinnae are from 40 cm to 1 m long, and the undersides have scales with spines along their margins. The stipes are thick, black, very rough to the touch, and are similarly covered in black scales with marginal spines. S. medullaris can be readily distinguished from related species by the hexagonal stipe scars on the trunk, and by the scales with spines on their margins.
Sphaeropteris medullaris will grow from fresh spores. Plants are easy to transplant when they are young. They are hardy in various conditions once established.
Location: Sun or part
Hardiness zones: 8-11
Spores per pack: 5
Germination: It is important to use a sterile seed-start mix, or sterile a mix with boiling water, before planting. Use a pot with holes so water can drain. When cool, sow on the surface of the mix. Watering should be done from the base only (from a bottom tray), as watering from the surface will bury the seeds and they cannot grow. Cover the pot with clear plastic, and keep in a well lit location as light is required for germination. Do not place in direct sun. The ferns can take weeks or months to germinate.
