From Common Forest Trees of Hawaii

Āulu
Rockia sandwicensis
Verbena/Four-O'Clock family (Nyctaginaceae)

Native species ()

Small to medium-sized native tree of dry forests, recognized from a distance by the dark green color of the large oblong leathery leaves. To about 50 ft (15 ) high with up to three trunks 1–2 ft (0.3–0.6 ) in diameter. Bark dark gray, smoothish to finely fissured. Inner bark is whitish, slightly bitter. Twigs light gray, with large raised half-round leaf-scars.


©2012 Forest And Kim Starr
Leaves hairless, with slender leaf-stalks of 1 1⁄4–2 inches (3–5 ). Blades large, oblong, 4–12 inches (10–30 ) long and 2 1⁄4–6 inches (6–15 ) wide, leathery, blunt, rounded, or slightly notched at broad and rounded at base, not on edges, upper surface shiny dark green with inconspicuous side veins, paler beneath.

Flower clusters rounded on stalks of 1 1⁄4–5 1⁄4 inches (3–6 ) at leaf bases. Male and female flowers are many, on different trees (), with 2–3 or at base and narrow greenish tubular about 1⁄4 inch (6 ) long, finely hairy, fragrant. Male flowers many, stalkless in rounded head about 2 inches (5 ) in diameter, consisting of deeply 5–6- tubular with five short about 20 minute sterile inside tube, and with narrow slender and enlarged fringed

(anthocarp) cylindrical, about 1 1⁄2 inches (4 ) long and very narrow, widest below middle, composed of enlarged with at and many faint lines and enclosing the narrow one-seeded () with at

Wood whitish, soft, very lightweight and porous, brash, not used. Tends to separate or “honeycomb” when dried. Highly susceptible to fungal stain. Branches are brittle and easily broken.

Widespread in dry forests through the islands, especially at 2000–2500 ft (610–762 ) altitude.

Special areas
Kokee, Waimea Arboretum

Range
Hawaiian Islands only

Other common name
pāpala kēpau

Botanical
Pisonia sandwicensis Hillebr

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

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

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.

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.

cm -- A centimeter which is about 0.4 inches.

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

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

Bracts are modified leaves associated with a flower.

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

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.

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

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

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

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

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

stigma - The tip of a pistil that receives the pollen.

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.

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

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

achene -- a type of simple dry fruit produced by many species of flowering plants. For example, a rose hip holds a few achenes.