From Common Forest Trees of Hawaii

Kanawao
Hydrangea arguta
Hydrangea/Mockorange family (Hydrangeaceae)

Native species ()

Kanawao is one of the most common shrubs in the understory of Hawaii’s rainforests, sometimes a small tree. This handsome plant is recognized by the large narrowly elliptical or leaves with finely edges and many long curved side veins, paired or three at a and by the large clusters of many small round bluish or dark red berries with narrow ring at tip.


©2011 Forest And Kim Starr
An shrub of 5–10 ft (1.5–3 ) or small tree to 20 ft (6 ). Bark gray brown, smoothish, slightly fissured. Inner bark is pinkish, astringent. Twigs stout, slightly succulent, hairy when young, with large raised half-round leaf-scars.

Leaves two or three at a ( or ), with stout fleshy leafstalk 3⁄4–2 inches (2–5 ) long, grooved above and enlarged at base. Blades large, narrowly elliptical or 4–10 inches (10-25 ) long and 1 1⁄2–3 1⁄2 inches (4–9 ) wide, long- or short-pointed at both ends, often widest beyond middle, slightly thick and leathery, with finely edges, upper surface shiny dark green and hairless with veins often sunken, lower surface light green with raised veins finely hairy.

Flower clusters () are and erect, broad, flattened or rounded, 2–4 1⁄2 inches (5–11 ) long and broad, with many short-stalked small flowers, male and female on different plants (). Male flowers about 1⁄2 inch (13 ) long and broad, composed of short with five pointed of five spreading petals almost 3⁄8 inch (10 ) long, white or tinged with blue or pink, 10 spreading nearly 1⁄2 inch (13 ) long, and small nonfunctioning Female flowers about 3⁄8 inch (10 ) long, composed of cup () bearing 5- 1⁄8 inch (3 ) long, five petals 1⁄16 inch (1.5 ) long, and with inferior five-celled short and five rounded stigmas.

() round, 3⁄8 inch (10 ) in diameter, bluish or dark red, fleshy. Seeds many, elliptical, minute.

Common and widespread in wet forests at low and middle altitudes of 1000–6000 ft (305–1829 ) through the Hawaiian Islands.

Special areas
Haleakala, Volcanoes.

Range
Hawaii only

Other common names
pu‘aha‘nui, kanawau, kupuwao, pi‘ohi‘a, akiahala, nawao

Botanical
Broussaisia arguta Gaud.
Broussiasia pellucida Gaud.
B. arguta var. pellucida (Gaud.) Fosberg.

This species is the only native Hawaiian example of its family, though several others have been introduced as ornamentals. Two varieties differing in leaf arrangement and flower color originally named as separate species have been distinguished.

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

cm -- A centimeter which is about 0.4 inches.

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

corymb -- a much-branched inflorescence with the lower flowers having long stems.

dioecious -- When male and female reproductive structures are on separate plants.

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

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.

terminal -- Located at the end (the tip or the apex).

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

obovate -- Teardrop-shaped, stem attaches to tapering point.

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.

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

In an opposite leaf arrangement the leaves come in pairs with one leaf on each side of a stem.

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.

fruit -- any seed-bearing structure in flowering plants. It is formed from the ovary after flowering.

whorled -- The leaves are arranged in whorls of 3 or more leaves along the stems of a plant.

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.

The hypanthium or floral cup is a cup-like structure formed by the fused bases of the stamens, petals, and sepals.

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.

The botanical term "berry" is different from common usage. Strawberries and raspberries are not berries. But a tomatoe is. A true berry is a fruit with the seeds immersed in the pulp.

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.