At first glance, our specimen--a fountain-shaped tree--would seem to be a fig (Ficus), judging from its alternate, evergreen, petiolate, leathery, obovate leaves (twelve to twenty centimeters in length) with a smooth edge (entire leaf margin); it even has a deciduous stipule at the base of the leaf. But this is Corynocarpus laevigata J. R. & G. Forster, one of only five species in Corynocarpaceae, a family of eastern Australasia and New Zealand. New Zealand laurel, or karaka, is occasionally grown as a shade plant within the subtropical "avocado belt" of maritime and near-coastal California, where freezing rarely occurs and fog is common. At MEMBG, two eight-meter multiple-stemmed trees of Corynocarpus thrive beneath the shade of Eucalyptus deglupta and other trees next to the Hawaiian section. The bark is brownish, actually bicolored gray of fibrous tissues and patches of reddish-brown cork cells.
Knowing just one obscure character, an expert botanist might be able to identify this by a leaf alone. With a good hand lens, tiny pits and bumps can barely be seen on each smooth (glabrous) leaf surface (laevigata means smooth). A very unusual multicellular hair forms in this shallow pit, and on the opposite leaf surface, a bump arises. The toughness of the leaf results from the thick-walled cells that cover it--one epidermal and two hypodermal layers-and clusters of fibers along the leaf veins. Another interesting feature of the leaf is that, after being removed from a plant, it remains green and fresh for several weeks.
Flowers of C. laevigata are formed on a branched inflorescence (a panicle) in which flowers develop from the bottom to the tip. The dormant, terminal bud forms in March as a panicle of 100 to 200 flowers, each less than five millimeters in diameter and not at all showy, but numerous flowers on a panicle may open each day. A flower has five greenish sepals and five off-white petals. Each of the five short stamens is fused to the base of a petal, but there are also five sterile stamens, called staminodes. A staminode in this species appears like a narrow petal but has an attached nectary, which looks like a young, small kernel of yellow corn. The pistil develops into a drupe, somewhat club-shaped (coryne = club; carpus = fruit), usually with a single seed. Fruits are very toxic and bitter, containing the compound karakin, but seeds are edible if roasted and were consumed as a staple food by the Maori of New Zealand.