From Common Forest Trees of Hawaii

Chamisso's Manfern
Cibotium chamissoi
Manfern family (Cibotiaceae)

Native species ()

This treefern is limited to wet forests of the island of Hawaii. It is recognized by the slender smooth trunk, by the leaf-stalks appearing hairless but covered with soft matted dull brown hairs with masses of pale, dull gray brown, narrow flattened hairlike on enlarged base and lower part; and by the leaf segments light green beneath.


©2010 David Eickhoff
A shrub or sometimes small tree with slender unbranched trunk to 20 ft (6 ), and 4–6 inches (10–15 ) in diameter, and with erect and nearly horizontal spreading leaves adding as much as 6 ft (1.8 ). Lower part of the trunk is smooth, and upper the part bears dead broken leaves.

Leaves () several, erect and spreading, the oldest dying and bending down along the trunk and breaking off cleanly, very large, feathery, divided 3 times (), mostly 5–6 ft (1.5–1.8 ) long. Leafstalk or axis () stout, flattened above, the enlarged base and lower part with masses of pale dull brown hairlike 1 1⁄4–2 inches (3–5 ), beyond green and hairless. The main axis bears many pairs of branches () to 2 1⁄2 ft (0. 8 ) long, further divided. Branches (pinnules) have many pairs, narrowly lance-shaped, 5–6 inches (13–15 ) long and 3⁄4 inch (2 ) wide, mostly with very short stalk at base, further divided or almost to Segments or many, nearly paired, oblong narrow rounded, to 3⁄8 inch (10 ) long and 3⁄16 inch (5 ) wide, with edges turned under and finely wavy, thin, upper surface light green with inconspicuous veins, lower surface dull light green with tiny cobwebby hairs.

Older leaf segments bear, on lower surface at ends of veins and on edges, two rows of seven or fewer yellowish boxlike cups (indusia) more than 1⁄32 inch (1 ) wide, each containing masses of dark brown cases (), which shed masses of microscopic abundantly.

The uses are similar to those described for the first species of treefern, but the stem is rarely large enough in diameter to be sawed or even bucked into “pots.”

Widespread in wet forests at low and middle altitudes; of 800–6000 ft (244–1829 ) on the Island of Hawaii. An understory plant in ‘ōhi‘a forests, often abundant in thickets.

Special area
Hawaii Volcanoes National Park, uncommon except in ‘Ōla‘a tract

Range
Island of Hawaii only

Other common name
hāpu‘u

mm -- millimeter. About 1/25th of an inch.

scale -- A very small leaf around a dormant bud. Also other things that might remind one of fish scales on the surface of ferns, stems and the like.

cm -- A centimeter which is about 0.4 inches.

pinnae -- the primary segments of a compound leaf.

frond -- a large, divided leaf. The leaves of most ferns are fronds.

spores are produced by ferns, horsetails, and other primitive plants. Spores are like tiny seeds, but they lack food for the plant embryo. Because spores are easily carried aloft by the wind, they allow ferns and horsetails to reproduce asexually across considerable distances.

midrib -- The central and most prominent vein of a leaf or leaf-like thing.

m -- A meter is about 10% larger than a yard.

lobe -- Rounded parts of a leaf (or other organ). Lobes bulge out about 1/4 of the leaf diameter.

pinnate -- A compound leaf with two rows of leaflets.

A stipe is a small stalk that supports some other structure. In ferns, the stalk of a frond; generally a small stalk.

sporangium is the enclosure in which spores are formed.

endemic -- when restricted to a certain country or area.