Manual of the New Zealand Flora/Rutaceæ

From Wikisource
Jump to: navigation, search
Manual of the New Zealand Flora by Thomas Frederick Cheeseman
Order XIV: Rutaceæ

Order XIV. RUTACEÆ .

Trees or shrubs, very rarely herbs, plentifully supplied with pellucid glands tilled with an aromatic or pungent essential oil. Leaves opposite or alternate, simple or compound, exstipulate. Flowers regular, hermaphrodite or rarely unisexual. Calyx 4–5-lobed or divided into as many free sepals, imbricate. Petals the same number, hypogynous or slightly perigynous, imbricate or valvate. Stamens usually free, hypogynous, as many or twice as many as the petals, rarely more numerous; anthers 2-celled, versatile. Disc placed between the stamens and ovary, usually annular, entire or lobed or crenate. Ovary of 4–5 free or connate carpels; styles as many, free at the base, united above; ovules usually 2 in each carpel. Fruit very various, sometimes of 4–5 2-valved cocci, or a berry or drupe, rarely a capsule with loculicidal dehiscence. Seeds generally solitary in each cell; albumen fleshy or wanting; embryo large, straight or curved, radicle superior.

As defined by Hooker and Bentham in the "Genera Plantarum," this is a large and heteromorphous order, comprising between 80 and 90 genera and nearly 700 species. Most of the species are either tropical or inhabit South Africa or Australia. They are comparatively rare in the north temperate zone. The chief characteristic of the order is the presence of an essential oil, which is usually abundant in the leaves and young growing parts, often giving them an aromatic odour and bitter or pungent taste. The orange, lemon, citron, lime, &c., are the chief economic species. The two New Zealand genera are also found in Australia, and Melicope extends into the Pacific islands as well.

Leaves simple, petiole terete. Flowers 5-merous 1. Phebalium.
Leaves compound, or if simple with the petioles winged. Flowers 4-merous 2. Melicope.

1. PHEBALIUM, Vent.

Shrubs. Leaves alternate, simple, entire or slightly toothed, pellucid-dotted. Flowers usually in axillary or terminal corymbs, rarely solitary. Calyx small, 5-lobed or -partite. Petals 5, imbricate or valvate. Stamens 8–10, longer or shorter than the petals; filaments filiform, glabrous. Ovary 2–5-partite almost to the base; style simple; stigma small, capitellate; ovules 2 in each cell, superposed. Cocci 2–5, truncate or rostrate; endocarp cartilaginous and separating elastically. Seeds usually solitary.

A genus of 28 species, all of which are confined to Australia with the exception of the present one, which is endemic in New Zealand.

1. P. nudum, Hook. Ic. Plant. t. 568.—A graceful much-branched perfectly glabrous shrub 4–12 ft. high; branchlets slender, with reddish bark. Leaves alternate, 1–112in. long, linear-oblong or narrow oblong-lanceolate, coriaceous, obtuse, obscurely crenate, narrowed into short petioles or almost sessile, pellucid-dotted. Flowers 13 in. diam., white, fragrant, in terminal many-flowered corymbs; pedicels short, scurfy. Calyx very small, with 5 broad lobes. Petals 5, lanceolate or linear, obtuse; margins involute. Stamens much longer than the petals. Cocci 1–4, but usually only 1 or 2 ripen, obtusely rhomboid, wrinkled, splitting into 2 valves.—Raoul, Choix, 48; Hook. f. FI. Nov. Zel. i. 44; Handb. N.Z. Fl. 39; Kirk, Students' Fl. 85.

North Island: Hilly forests from Kaitaia southwards to the Thames River, ascending to 2.500 ft. Mairehau. October–December.

Highly aromatic in all its parts. The flowers have been used for the extraction of a perfume.

2. MELICOPE, Forst.

Trees or shrubs. Leaves opposite or alternate, simple or 3-foliolate, rarely pinnate, pellucid-dotted. Flowers usually small, often unisexual, in axillary or terminal few- or many-flowered cymes or panicles. Sepals 4. Petals 4, valvate or imbricate, with inflexed tips. Stamens 8, inserted at the base of the disc; filaments subulate. Ovary 4-lobed almost to the base, 4-celled; style single or 4 coalescing into 1; stigma capitate, 4-lobed; ovules 2 in each cell. Cocci 1–4, distinct, spreading, 2-valved, 1-seeded; endocarp cartilaginous or horny, separating. Seeds usually solitary; testa crustaceous, shining; albumen fleshy; embryo straight or slightly curved.

Besides the two species described below, both of which are endemic, there are 10 or 12 from the Pacific islands, 2 from tropical Asia, and 3 from Australia.

Leaves large, 3 foliolate (often 1-foliolate in var. Mantellii); petioles terete 1. M. ternata.
Leaves small, 1-foliolate; petioles flat 2. M. simplex.

1. M. ternata, Forst. Char. Gen. 56.—A much-branched perfectly glabrous small tree 12–20 ft. high. Leaves opposite, 3-foliolate; leaflets 2–4 in. long, linear-obovate or elliptic-oblong or oblong-ovate, acute or obtuse, entire, finely pellucid-dotted. Flowers 13 in. diam., greenish, often unisexual, in axillary trichotomous panicles usually longer than the petioles; pedicels short. Petals ovate-oblong, longer than the stamens, concave. Ovary glabrous; style short, stout. Cocci 4, coriaceous, spreading, strongly wrinkled and punctate. Seed black and shining, attached by a slender funicle, often protruding from the half-open valves.—A. Rich. Fl. Nouv. Zel. 293; A. Cunn. Precur. n. 582; Hook. Ic. Plant. t. 603; Raoul, Choix, 48; Hook. f. Fl. Nov. Zel. i. 43; Handb. N.Z. Fl. 40; Kirk, Forest Fl. t. 66; Students' Fl. 86. Entoganum lævigatum, Gærtn. Fruct. i. 331, t. 68.

Var. Mantellii, Kirk, Forest Fl. t. 66.—Smaller, much branched; branches strict. Leaves usually much smaller, 3- or 1-foliolate; leaflets rounder, often obscurely crenate. Panicles 3–6-flowered.—M. Mantellii, Buch. in Trans. N.Z. Inst. iii. (1871) 212.

Kermadec Islands, North Island: Common in lowland districts. South Island: Marlborough and D'Urville Island, local. Ascends to 1000 ft. Wharangi. September–October.

The Kermadec Island specimens have much larger and more obtuse leaflets, but do not seem to differ in other respects. Var. Mantellii combines the characters of M. ternata and M. simplex to an extraordinary degree, and may be a hybrid between those species.

2. M. simplex, A. Cunn. Precur. n. 583.—A glabrous shrub 6–12 ft. high, with slender twiggy branches. Leaves alternate or fascicled, rarely opposite, in young plants 3-foliolate, in mature 1-foliolate; petiole flattened or narrowly winged; leaflets small, jointed on the top of the petiole, 1234 in. long, rhomboid-obovate or rounded, obtuse, doubly crenate, pellucid-dotted. Flowers often unisexual, small, greenish-white; peduncles usually several together, axillary, longer than the petioles, 1- or 3-flowered. Stamens longer than the petals in the male flowers, shorter in the females. Ovary hirsute; style very short in the male flowers, longer in the females; stigma obscurely 4-lobed. Fruit as in M. ternata, but smaller.—Hook. Ic. Plant. t. 585; Raoul, Choix, 48; Hook. f. Fl. Nov. Zel. i. 43; Handb. N.Z. Fl. 40; Kirk, Forest Fl. t. 68; Students' Fl. 86. M. parvula, Buch. in Trans. N.Z. Inst. xx. (1887) 255. Astorganthus Huegelii, Endl. Cat. Hort. Vindob. ii. 196.

North and South Islands: Abundant from the North Cape to Southland, ascending to 2000 ft. September–November.

The flowers are occasionally cleistogamic. (See a paper on the subject by Mr. G. M. Thomson, in Trans. N.Z. Inst. xxiv. 416.)