From Common Forest Trees of Hawaii

Bobea sandwicensis
Madder family (Rubiaceae)

Native species ()

The Bobea, common name ‘ahakea, is known only from the Hawaiian Islands and has 4 or fewer species of trees distributed through the islands. They have small paired pale green leaves with paired small pointed that shed early, 1–7 small flowers at leaf bases, with tubular greenish the four overlapping in bud, and small round black or purplish (), mostly dry, with 2–6 nutlets. This species, described below, will serve as an example.

©2009 David Eickhoff
Medium-sized tree to 33 ft (10 ) high and 1 ft (0.3 ) in trunk diameter. Bark gray, smoothish, slightly warty, fissured, and scaly. Inner bark is light brown, bitter. Twig light brown, with tiny pressed hairs and with rings at

Leaves with pinkish finely hairy leaf-stalks of 3⁄8–5⁄8 inch (1 –1. 5 ) and paired small pointed hairy 1⁄8 inch (3 ) long that form a bud and shed early. Blades are or elliptical, 2–3 1⁄2 inches (5–9 ) long and 1–2 inches (2.5–5 ) wide, short- to long-pointed at and blunt at base, with edges straight or slightly wavy, thin. Upper surface slightly shiny green, hairless, with pinkish and few curved side veins; lower surface light green with pinkish raised and tiny hairs in vein angles.

Flowers mostly 1–3 at leaf bases on slender stalks of 1⁄4–1 inch (6–25 ), 5⁄16 inch (8 ) long, finely hairy, composed of greenish base () 1⁄8 inch (3 ) long; of 4 spreading elliptical green to 3⁄16 inch (5 ) long; whitish green 1⁄4 inch (6 ) long with narrow cylindrical tube and four spreading narrow overlapping in bud; four stalkless in notches of and with inferior short and 4–6-

() round, about 3⁄8 inch (1 ) in diameter, purplish black and slightly shiny, with tiny pressed hairs, with 4 enlarged rounded more than 1⁄4 inch (6 ) long remaining at containing 2–6 stones (nutlets), each 1-seeded.

Wood yellow, hard and heavy, straight-grained. Used by the Hawaiians for the carved end covers and gunwales of canoes for its yellow appearance and for its wearability. Modern canoes are often painted yellow at the gunwales to simulate ‘ahakea wood. Also used for poi boards and paddles.

Scattered in wet to dry forests and on open lava flows at 300–4000 ft (105–1220 ) elevation.

Maui, Lanai, Molokai, and Oahu

Bobea hookeri Hillebr.

This was named in 1830 for Bobe-Moreau, physician and pharmacist in the French Marine. Three other species are found on the large islands of Hawaii.

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

cm -- A centimeter which is about 0.4 inches.

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

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

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

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.

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

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

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.

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.

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.

drupe -- A fruit in which an outer fleshy part surrounds a hardened shell containing a seed. A peach is a drupe. A raspberry is composed of drupelets.

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.

ovate -- Oval, egg-shaped, with a tapering point.

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.

genus -- A subdivision of a botanical Family in which all members have a significant number of similar characteristics.