From Common Forest Trees of Hawaii

Hau
Hibiscus tiliaceus
Mallow family (Malvaceae)

Native species (indigenous)

This common small tree of lowlands, especially shores, through the islands, is characterized by large funnel-shaped bright yellow flowers 3–3 1⁄2 inches (7.5–8 ) long and broad, usually with dark red “eye spot” inside, and by long-stalked heart-shaped and nearly round leaves with mostly seven or nine main veins from base, whitish gray hairy beneath.


©2010 Forest And Kim Starr
Small native tree 13–33 ft (4–10 ) high, with short crooked trunk to 6 inches (15 ) in diameter and with a broad of widely spreading or crooked branches, or a shrub with many branches forming dense thickets. Bark gray or light brown, smooth; inner bark fibrous. Twigs stout, with rings at becoming brown and hairless. Young twigs, leaf-stalks, lower leaf surfaces, and seed capsules densely covered with minute whitish gray star-shaped hairs.

Leaves with leaf-stalks of 2–5 inches (5–13 ) and with two large short-pointed whitish hairy () 1–1 1⁄2 inches (2.5–4 ) long, shedding early and leaving a ring scar. Blades 4–7 inches (10–18 ) long and broad, sometimes larger, abruptly short- or long-pointed at and heart-shaped at base, rarely wavy on edges, slightly thickened and leathery, shiny yellow green and hairless on upper surface, lower surface with three narrow near base of main veins.

Flower clusters () at or near ends of twigs, branching. Flowers are many, few in each cluster, each with whitish hairy stalk of 3⁄4–2 inches (2–5 ) and gray green hairy cup () 3⁄4 inch (2 ) long usually with 9–10 narrow pointed 1–1 1⁄4 inches (2.5–3 ) long, gray green hairy, tubular with five narrow long-pointed Petals five, yellow, usually with dark red spot at base inside, 2 1⁄2–3 1⁄2 inches (6–9 ) long, rounded but broader on one side, with tiny star-shaped hairs on outer surface, united at base. numerous on column about 2 inches (5 ) long united with at base. has densely hairy conical five-celled long slender and five broad stigmas. Flowers opening and closing the same day, the petals withering and turning to orange and later to red.

Seed capsules are elliptical, 1–1 1⁄4 inches (2.5–3 ) long, long-pointed, gray green hairy, splitting into five parts and breaking open the and which remains attached. Seeds, three from each cell, brownish black, 1⁄8–3⁄16 inch (3–5 ) long, hairless. Flowering and fruiting probably through the year.

Sapwood is whitish and heartwood dark greenish brown. Wood moderately soft and porous, and moderately heavy ( gr. 0.6). It has been used sparingly by Hawaii’s craftwood industry for carved and turned bowls and bracelets. The wood so used is mostly sapwood, so that the mottled dark heartwood inclusions give a marble-like appearance. Freshly cut wood has an odor similar to coconut.

Hawaiians used the wood for outriggers of canoes, floats for fish nets, long spears for games, and for sticks of kites. Fires were started by friction by rubbing a pointed stick of a hardwood such as olomea (Perrottetia sandwicensis), against a grooved piece of the much softer hau wood. Hau is preferred by local Boy Scout troops for earning fire starting merit badges.

An important use of the tough fibrous inner bark, here and wherever this species grows, is for ropes and cords. Several long strips are braided together depending upon the strength needed. It was beaten into tapa or bark cloth and used for mats. The “grass” skirts exported for hula dancers from Samoa and elsewhere in the Pacific are actually made of hau fiber. The same material is used to strain the beverage kava in Samoa. Elsewhere, in times of famine the bark, roots, and young leaves were eaten. Flowers, roots, and bark served in folk remedies.

Hau is planted through the tropics as an ornamental for the showy flowers and as a shade tree. Branches can be trained over trellises to form arbors. Easily propagated by cuttings and started in fence rows as living fence posts. The long spreading branches form roots upon contact with the ground, making dense thickets and in coastal swamps aiding in building the land. Classed as a honey plant. A weed in pastures, rangelands, and waste places (Haselwood and Motter 1966).

Common in lowlands and especially on beaches through the Hawaiian Islands to about 1500 ft (457 ).

Special areas
Keahua, Waimea Arboretum, Tantalus, Haleakala, Volcano

Range
Seashores through tropics, native probably in the Old World. Common and widespread through the Pacific Islands and regarded as native in Hawaii. Naturalized in the New World, including Florida, Puerto Rico, and Virgin Islands.

Other common names
linden hibiscus, mahoe; emajagua (Puerto Rico, Spanish); pago (Guam, N. Marianas); ermall (Palau); gaal (Yap); kilife (Truk); kalau (Pohnpei); lo (Kosrae, Marshalls); fau (Am. Samoa).

Botancial
Paritium tiliaceum (L.) St.-Hil., Juss., & Camb., Pariti tiliaceum (L.) Britton.

Minor variations have been observed. Examples are forms with double flowers, white petals with maroon dot at base, and pure yellow petals. One variation introduced into Hawaii from Guadalcanal is an erect tree to 66 ft (20 ) tall.

The English name mahoe is a corruption of the Spanish common name majagua or emajagua. That American Indian word is applied in tropical America to several unrelated trees with useful fibrous bark.

node -- The point at which there is attached growth, as in the place where each leaf is attached.

sp. -- The abbreviation for "species". The plural is "spp". When used it sometimes means that the exact species is unknown. For example, "Aster sp" would mean some species within the Aster genus but the writer may not know exactly which species.

cm -- A centimeter which is about 0.4 inches.

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

Glands are plant structures that secrete liquids, salts or other substances. Glands often appear as hairs with a drop of liquid at the end.

stipule -- A leaf-like structure that occurs where the leaf joins the stem; stipules often occur in pairs.

style -- This is a long and thread-like structure that connects the stigma with the ovary. A flower may have a single style, or several of them.

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.

The apex is the tip or the furthest point from the attachment.

alternate -- leaves alternate along the main stem and are attached singly.

cross -- To make something interbreed. The act of hybridization.

Involucre is the name given to the circle or spiral collection of bracts around a flower-cluster.

Like the teeth on a saw, leaves and other surfaces can have toothed edges.

A panicle is a much-branched inflorescence. The bottom flowers in a panicle open first.

A pistil is the female structure of many flowers. It contains one or more carpels. Each carpel contins an ovary, style and stigma. The stigma receives the pollen which grows thru the style to reach the ovary.

An evergreen tree retains a large portion of its green leaves all year.

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

basal -- at the base, situated or attached at the base.

calyx -- the sepals of a flower, typically forming a whorl that encloses the petals and forms a protective layer around a flower in bud.

canopy -- The foliage of a tree; the crown. Also the upper layer of a forest.

synonym -- In botany a synonym is a species name that at one time was thought to be the correct name for a plant but was later found to be incorrect and has been replaced by a new name.

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

corolla -- The name for all the petals of a flower taken together.

stamen -- the pollen-producing reproductive organ of a flower; The stamen consists of an anther supported by a filament.

An ovary is a part of the female reproductive organ of the flower. Above the ovary is the style and the stigma, which is where the pollen lands and germinates to grow down through the style to the ovary.

prostrate -- Laying flat on the ground.