Order XXII. LEGUMINOSÆ.
Herbs, shrubs, or trees, of very various habit. Leaves usually alternate, stipulate, compound, rarely simple, sometimes wanting. Flowers generally irregular, hermaphrodite, occasionally regular and polygamous. Sepals 5, usually cohering into a more or less deeply divided calyx, sometimes free, often unequal, occasionally 2-lipped. Petals 5, seldom fewer, perigynous or rarely hypogynous, either papilionaceous or more or less regularly spreading. Stamens 10, rarely less or more, perigynous or almost hypogynous; filaments either free or all connate into a tube surrounding the ovary, or more generally 9 of them united and 1 free. Ovary free, 1-celled, consisting of a single carpel; style simple; ovules 1 to many, attached to the ventral suture. Fruit a pod splitting open along both sutures, rarely indehiscent or transversely breaking up into 1-seeded joints. Seeds nearly always exalbuminous; embryo with large foliaceous or amygdaloidal cotyledons and a short radicle.
Suborder PAPILIONACEÆ.
All the indigenous genera belong to this suborder, which is characterized as follows: Corolla irregular and papilionaceous, seldom almost regular. Petals imbricate, the uppermost (or standard) always outside in the bud. Stamens definite, usually 10.
With the exception of Compositæ, this is the largest order of flowering plants, comprising over 400 genera and about 7000 species. Next to Gramineæ, it is the most serviceable to man for food; and it produces more substances used in the arts and medicine than any other order. Its distribution is practically world-wide; but it is singularly rare in New Zealand, the proportion of species being much smaller than in any other country of equal size. In fact, the paucity of Leguminosæ is one of the most remarkable peculiarities of the New Zealand flora, especially taking into account that the order is the one most strongly developed in Australia, the nearest land-area to New Zealand. Of the 7 indigenous genera, Carmichælia has an outlying species in Lord Howe Island, but is otherwise restricted to New Zealand; while the two closely allied genera Corallospartium and Notospartium are endemic. Clianthus has 1, or perhaps 2, species in Australia, and 1 in the Malay Archipelago; Swainsona is largely represented in Australia; while Canavalia and Sophora are widely distributed in warm climates. A list of the naturalised species, with references to descriptions, will be found in the appendix.
| * Shrubs, sometimes very small; branches flattened, compressed or nearly terete, grooved or striate, leafless or nearly so when adult. | |
| Branches stout, terete, deeply grooved. Pods compressed, 1-seeded, dehiscing along the sutures | 1. Corallospartium. |
| Branchlets compressed or terete. Pods short, few-seeded; valves falling away from the persistent thickened sutures, to which the seeds remain attached, or rarely the pod is indehiscent | 2. Carmichælia. |
| Branchlets terete or compressed, slender, pendulous. Pods narrow-linear, torulose, 2–10-seeded, indehiscent | 3. Notospartium. |
