annular or unilateral, rarely wanting. Stamens 5–10, in the great majority of the order (but not in the New Zealand genera) inserted inside the disc at the base of the ovary, more rarely outside or on the disc, sometimes unilateral; anthers basifixed or versatile, 2-celled. Ovary free, central or excentric, entire lobed or partite, 1–4-celled; style simple or divided, usually terminal; ovules 1–2 in each cell, seldom more. Fruit very various, capsular or indehiscent, dry or succulent, entire or lobed, sometimes winged. Seeds globose or compressed, with or without an aril; albumen wanting or more rarely present; embryo generally thick, sometimes folded or spirally twisted, radicle short, inferior.
A polymorphous order, exceedingly difficult to characterize as a whole, and often separated into 3 or 4 distinct ones. As defined above, it comprises about 80 genera and between 600 and 700 species, many of them very imperfectly known. It is chiefly tropical, but extends through both of the temperate zones. The properties of the order are very various. The maples contain a sweetish sap, from which sugar is obtained. Several species of Nephelium, such as the Litchi and Longan, produce some of the most delicious of Asiatic fruits. Many species contain bitter or astringent principles, while others, as some of the American species of Serjania and Paullinia, are reputed to be poisonous. The two genera found in New Zealand belong to the tribe Dodonææ, which has regular flowers, stamens inserted outside the disc (not inside), and exalbuminous seeds. Alectryon is endemic, but Dodonæa is most abundant in Australia, extending also through the tropics of both hemispheres.
|Leaves simple in the New Zealand species. Disc wanting. Capsule membranous, often winged||1. Dodonæa.|
|Leaves pinnate. Disc 8-lobed. Capsule woody, turgid||2. Alectryon.|
1. DODONÆA, Linn.
Shrubs or small trees, often viscid with a resinous exudation. Leaves alternate, exstipulate. Flowers unisexual or polygamous, in terminal or axillary racemes or panicles, rarely solitary. Sepals 2–5, imbricate or valvate. Petals wanting. Stamens 5–10, usually 8; filaments short; anthers linear-oblong. Ovary 3–6-celled, with 2 ovules in each cell. Capsule membranous or coriaceous, 2–6-sided, septicidally 2–6-valved; valves winged at the back. Seeds 1–2 in each cell, lenticular or subglobose, compressed, with a thickened funicle but not arillate; embryo spirally coiled.
A genus comprising about 50 species, fully 40 of which are confined to Australia, the remainder scattered through the tropical or subtropical regions of both hemispheres. The New Zealand species is found in most warm countries.