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Manual of the New Zealand Flora.

Order LXV. PolygonaceÆ

Order LXV. PolygonaceÆ.

Herbs or shrubs or woody climbers. Leaves alternate or rarely opposite, simple, entire or serrulate. Stipules thin, scarious or membranous, forming a sheath round the stem. Flowers small, regular, usually hermaphrodite, herbaceous or coloured, often jointed on the pedicel, clustered in the axils of the leaves or in page 588spikes or racemes, often forming terminal panicles. Perianth inferior, persistent; segments 3–6, free or connate at the base, imbricate. Stamens 5–9, rarely more or less, hypogynous or perigy-nous; filaments capillary or subulate, free or connate at the base; anthers 2-celled. Ovary superior, compressed or 3-gonous; styles 1–3; ovule solitary, basal, orthtropous. Fruit a small hard inde-hiscent trigonous or compressed nut, usually enclosed in the persistent perianth. Seed erect, testa membranous; albumen copious, farinaceous; embryo variable in position, radicle superior.

A rather large order, spread over the whole world, but most abundant in the north temperate zone. Genera 30; species over 600. The roots of many species are nauseous and purgative, the medicinal rhubarb being a well-known instance. On the other hand, the stems and leaves are frequently acid and refreshing, as the garden-rhubarb and the common sorrel. Buckwheat (Fagopyrum) is the only edible plant of any consequence. Of the 3 New Zealand genera, Muehlen-beckia extends to Australia and South America; the remaining 2 are widely distributed in both hemispheres.

Flowers hermaphrodite. Perianth-segments 5, not succulent in fruit 1. Polygonum.
Flowers hermaphrodite. Perianth-segments 6, the 3 inner enlarging and closing over the fruit, not succulent 2. Rumex.
Flowers unisexual. Perianth-segments 5, enlarged and succulent in fruit 3. Muehlenbeckia.

1. Polygonum, Linn.

Herbs, rarely shrubby at the base. Leaves alternate; stipules membranous, usually tubular and closely sheathing the stem. Flowers small, hermaphrodite, clustered; clusters either axillary or in racemes or spikes or panicles; bracts and bracteoles membranous, ochreate; pedicels usually jointed. Perianth 5-partite, green or coloured; segments equal or the 2 or 3 outer ones the largest. Stamens 5–8. Ovary compressed or 3-gonous; styles 2 or 3, free or connate at the base; stigmas usually capitellate. Nuts compressed or 3-gonous, included in the persistent perianth. Seed albuminous; embryo excentric or lateral; radicle long, superior.

A large and almost cosmopolitan genus, including over 150 species. The three found in New Zealand are all widely distributed.

* Stems prostrate. Flowers in axillary clusters.

Stems long, wiry, sparingly branched. Perianth ⅛ in. long. Nut minutely striate or punctate 1. P. aviculare.
Stems short, compactly branched. Perianth 1/12 in. long. Nut smooth and polished 2. P. plebeium.

** Stems erect or ascending above. Flowers in slender terminal spikes.

Leaves 2–5 in., lanceolate. Stipules ciliate and pilose. Spikes very slender, 1–2 in. long 3. P. serrulatum.

For references to several introduced species of Polygonum, see the list of naturalised plants appended to this work.

page 589
1.

P. aviculare, Linn. Sp. Plant. 362.—A glabrous rigid and wiry prostrate annual, much branched from the base; branches ½–2 ft. long, straggling, grooved, leafy throughout. Leaves scattered, sessile or shortly petioled, ⅓–1 in. long or more, linear-oblong to lanceolate or linear-lanceolate, rarely broader and elliptic-oblong, acute or obtuse, veins indistinct beneath, margins flat or recurved; stipules brown or reddish near the base, silvery-white above, scarious, lacerate to below the middle. Flowers small, 1/10–⅛ in. long, solitary or in clusters of 2–4 in the axils of nearly all the leaves, very shortly pedicelled. Perianth-segments oblong, obtuse, with a green centre and broad white margins. Nut ovoid, obtusely 3-gonous, very minutely striate or punctate.—Hook. f. Fl. Nov. Zel. i. 210; Handb. N.Z. Fl. 235; Benth. Fl. Austral. v. 267.

NoRth and South Islands: Roadsides and waste places from the North Cape to Foveaux Strait. Most probably an immigrant. Sea-level to 2500 ft. Knot-grass; Makakaka. November–March.

It is highly doubtful if this is indigenous anywhere outside Europe and northern Asia, although its present distribution is almost cosmopolitan. So far as its occurrence in New Zealand is concerned, I should certainly have relegated it to the list of naturalised plants had it not been for the positive opinion expressed in favour of its nativity by the late Mr. Kirk. Those interested in the subject should read the papers by Kirk and Travers printed in Vols. iv. and v. of the Trans. N.Z. Institute.

2.

P. plebeium, R. Br. Prodr. 420.—Habit of P. aviculare, but smaller and more compactly branched. Stems prostrate, glabrous or minutely scaberulous, 4–12 in. long, rarely more; branches slender, grooved. Leaves more closely placed than in P. aviculare, ⅙-½ in. long, linear to linear-oblong, rarely linear-spathulate, obtuse or subacute, midrib evident, margins flat or recurved; stipules short, hyaline, lacerate to the middle. Flowers small, 1/12–1/10 in. long, solitary or in clusters of 2–5 in the axils of most of the leaves; pedicels short. Nut smaller than in P. aviculare, rhomboid, obtusely 3-gonous, smooth and shining.—Benth. Fl. Austral. v. 267. P. Dryandri, Spreng. Syst. ii. 255; Hook. f. Fl. Nov. Zel. i. 210. P. aviculare var. Dryandri, Hook. f. Handb. N.Z. Fl. 236.

North and South Islands: From the Great Barrier Island and the Bast Cape southwards to the Bluff, but local in the North Island, most abundant in Canterbury and Otago. Sea-level to 3000 ft. November–March.

Very closely allied to P. aviculare, but apparently sufficiently distinct in the smaller size and more compact habit, smaller flowers, and smaller shining and polished nut. A common plant in Australia, tropical Asia, and some parts of Africa.

3.

P. serrulatum, Lag. Gen. et Sp. Nov. 14.—Stems slender, herbaceous, sparingly branched, prostrate and rooting below, ascending or erect above, glabrous, 9–24 in. long or more. Leaves shortly petiolate, 2–5 in. long, lanceolate or linear - lanceolate, page 590acuminate, narrowed to a rounded or subcordate base, membranous, glabrous or strigose on the midrib beneath, margins serrulate; stipules long, closely sheathing, ciliate and pilose with long erect hairs. Spikes terminal, very slender, simple or sparingly branched, 1–2 in. long; bracts narrow-turbinate, truncate, margins ciliate. Flowers 2–3 to each bract, small, reddish, 1/12 in. long. Perianth-segments oblong, obtuse, glabrous and eglandular. Stamens 5 or 6. Style-branches 2, rarely 3. Nut plano-convex with obtuse margins, rarely trigonous, smooth and shining.—P. minus var. decipiens, Hook. f. Handb. N.Z. Fl. 235. P. prostratum, A. Rich. Fl-. Nov. Zel. Ill (not of B. Br.); A. Cunn. Precur. n. 358; Raoul, Ghoix, 42; Hook. f. Fl. Nov. Zel. i. 209.

North and South Islands, Chatham Islands: Abundant along the sides of rivers or in lowland swamps from the North Cape to Canterbury. Tutu-nawai. November–March.

A widely distributed plant, ranging through south Europe, western Asia, Africa, and Australia. It differs from P. minus in the larger size, the more slender and much more erect habit, and in the longer and more ciliate stipules.

2. Rumex, Linn.

Perennial or annual herbs, very rarely shrubby. Leaves all radical or radical and cauline, often cordate or hastate at the base, entire or toothed or almost pinnatifid. flowers hermaphrodite or less commonly unisexual, small, green, in axillary clusters or whorls, often forming simple or panicled racemes. Perianth-segments 6, the 3 inner enlarging and closing over the fruit, margins entire or toothed, midrib often tubercled. Stamens 6. Ovary 3-gonous; styles short, filiform; stigmas fimbriate. Nut 3-gonous, included in the enlarged inner perianth-segments, angles acute. Embryo lateral.

A large genus of over 100 species, found in all temperate and many tropical countries, and including several common weeds of cultivation. Both the New Zealand species.are endemic.

Flowering - stems much divaricately branched, 6–18 in. high. Inner perianth-segments without tubercles, reticulate, margins usually with long curved spines 1. R.flexuosus.
Flowering - stems short, stout, depressed, 2–6 in. high. Inner perianth-segments tubercled; margins entire or with 1 or 2 short teeth 2. R. neglectus.

Several species of Rumex from the Northern Hemisphere have been introduced into the colony, and are now widely diffused, the most abundant being the English "docks" R. obtusifolius, R. crispus, and R. viridis; and the "sheeps" sorrel" R. acetosella. Descriptions of these will be found in any English Flora.

1.

R. flexuosus, Sol. ex Forst. Prodr, n. 515. — A glabrous perennial herb with a diffusely branched stem 6–18 in. high; branches slender, grooved, flexuous, divaricate. Leaves chiefly page 591radical, variable in size, 3–12 in. long, linear or linear-oblong, acute or obtuse, cuneate or truncate or cordate at the base, rarely-expanded or subhastate; margins flat or waved. Panicle at first open, but in an advanced fruiting stage the branches are often numerous, spreading and intricate; whorls remote, 4–12-flowered, the lower ones leafy; peduncles jointed near the base, curved, deflexed. Inner segments of the fruiting - perianth about 1/10 in. long, rhomboid, narrowed into a long acuminate tip, reticulated, without tubercles; margins entire or more usually furnished with 1–4 hooked spines on each side.—Hook. f. Fl. Nov. Zel. i. 211; Handb. N.Z. Fl. 237. A. Cunninghamii, Meissn. in D.C. Prodr. xiv. 62. E. Brownianus, A. Cunn. Precur. n. 360 (not of Camp.); Raoul, Choix, 42.

Kermadec Islands, North and South Islands: Abundant throughout. Sea-level to 4000 ft. December–March.

Very closely allied to the Australian R. Brownii, to which it was referred by Allan Cunningham, and from which it differs mainly in the more diffusely branched habit.

2.

R. neglectus, T. Kirk in Trans. N.Z. Inst. ix. (1877) 493. —A glabrous perennial herb 2–6 in. high; rootstock long, stout, often branched above. Leaves rosulate, 1–3 in. long, linear-oblong, obtuse, truncate or cuneate at the base, margins crenate-undulate; petiole almost as long as the blade. Flowering-stem short, stout, depressed, simple or with 1–2 branches from the base; dense-flowered or rarely elongated with the whorls interrupted; peduncles usually deflexed. Flowers hermaphrodite. Fruiting-perianth sub-campanulate, about ⅛ in. long, thickened at the base; outer segments oblong, obtuse, equalling the tube; inner rather longer, lanceolate, acute, with a tubercle on the midrib and 1 or 2 short teeth on each side.—Oliver in Hook. Ic. Plant, t. 1245. R. cunei-folius var. alismæfolius, Hook. f. Fl. Antarct. i. 67.

North Island: Pebbly beaches near Wellington, Kirk! South Island: Canterbury — Armstrong. Otago — Dusky Bay, Buchanan! Port Molyneux, Catlin River, the Bluff, Petrie! Stewart Island: Paterson's Inlet, Petrie! Auckland Islands: Sir J. D. Hooker, Kirk! November–March.

3. Muehlenbeckia, Meissn.

Large or small shrubs or undershrubs, often climbing, sometimes prostrate or diffusely spreading. Leaves alternate, petiolate, large or small, sometimes wanting; stipules short, loosely sheathing. Flowers polygamous or diœcious, small, whitish, fascicled within small sheathing bracts; fascicles axillary or arranged in axillary or terminal spikes, racemes, or panicles. Perianth deeply 5-partite; segments equal or the outer ones rather larger, often becoming white and succulent in fruit. Stamens 8, rarely fewer, affixed to the base of the perianth; filaments filiform; anthers page 592ovate, in the female flowers reduced to short and thick staminodia or altogether wanting. Ovary 3-gonous, in the male flowers small and rudimentary; styles 3, short; stigmas usually fimbriate. Nut obtusely or acutely 3-gonous, en closed in the usually more or less succulent perianth.

A small genus of about 15 species, found in Australia, New Zealand, the Pacific islands, and extra-tropical and Andine South America. Of the four, species described below, one is found in Australia and another in Norfolk Island, the remaining two are endemic.

Leaves 1–3 in., broad-ovate, acuminate, membranous. Flowers in much-branched panicles 1. M. australis.
Leaves ⅕–¾ in., broadly oblong or orbicular. Flowers in spikes, rarely panicled 2. M. complexa.
Leaves 1/10–⅓ in., ovate-oblong or orbicular. Flowers axillary, solitary or 2 together 3. M. axillaris.
Leaves wanting or if present linear. Male flowers in lax spikes; females in few-flowered fascicles 4. M. ephedrioides.
1.

M. australis, Meissn. Gen. Comm. 227.—A much-branched climber, covering shrubs or small trees, or trailing over cliffs or rocks; trunk stout, woody, sometimes 3 in. diam.; bark greyish; branches numerous, flexuous and interlaced, the younger ones grooved and angled, glabrous or faintly scaberulous. Leaves petio-late, 1–3 in. long, ovate or orbicular-oblong, apiculate or acuminate, rarely obtuse, cordate or truncate at the base, thin and membranous, quite glabrous, usually entire, but sometimes panduriform or 3-lobed, margins undulate-crisped; petioles ⅓–1 in. long; stipules deciduous. Panicles large, axillary and terminal, much branched, 1½–3 in. long or more. Flowers about ⅙ in. diam., greenish, diœcious; males with 8 stamens and the rudiment of an ovary; females with 8 blunt staminodia and a short triquetrous ovary; stigmas broad, fimbriate. Fruiting-perianth closed over the fruit, slightly succulent or almost herbaceous. Nut black, shining, 3-angled and 3-grooved, angles often twisted.—M. adpressa, Hook. f. Handb. N.Z. Fl. 236 (not of Meissn). Polygonum australe, A. Rich. Fl. Nouv. Zel. 178; A. Cunn. Precur. n. 355; Raoul, Choix, 42. P. adpres-sum, A. Cunn. I.c. n. 356 (not of Labill.). Coccoloba australis, Forst. Prodr. n. 176.

North and South Islands, Stewart Island, Chatham Islands: Common from the Three Kings Islands and the North Cape southwards. Sea-level to 2000 ft. November–April.

Also found in Norfolk Island, and very closely allied to the Australian M. adpressa, Meissn.

2.

M. complexa, Meissn. Gen. Comm. 227. — Forming dense thick and elastic prostrate masses many feet in diam., or climbing over bushes or rocks. Stems slender, tough and woody, much interlaced; branches very numerous, flexuous, terete, the ultimate ones pubescent with short stiff hairs; bark dark red-brown. page 593Leaves petiolate, exceedingly variable in size and shape, even on the same plant, ⅕–¾ in. long or more, broadly oblong or obovate or orbicular, rounded or retuse at the tip, rarely subacute, cordate or truncate or rounded at the base, often contracted in the middle, sometimes 3-lobed, quite smooth, glabrous or the petiole puberulous, coriaceous or almost membranous, margins even, entire; stipules deciduous. Spikes axillary and terminal, long or short, simple or compound, glabrous or puberulous, sometimes reduced to 2 or 3 flowers, at other times forming a panicle 1–1½ in. long or more. Flowers small, diœcious. Stamens 8. Stigmas very broad, fimbriate. Fruiting-perianth much enlarged, often ¼–⅓ in. diam., succulent, waxy-white, forming a fleshy cup surrounding the fruit, in some varieties unaltered and herbaceous. Nut black, shining, deeply triquetrous.—Hook. f. Handb. N.Z. Fl. 236. M. microphylla, Col. in Trans. N.Z. Inst. xx. (1888) 204. M. paucifolia, M. trilobata, and M. truncata, Col. I.c. xxi. (1889) 99–101. Polygonum com-plexum, A. Cunn. Precur. n. 357; Raoul, Ghoix, 42; Hook. f. Fl. Nov. Zel. i. 210.

North and South Islands: Abundant throughout, ascending to 2000 ft. Pohuehue. November–April.

Varying much in the size and shape of the leaves, the degree of development of the spikes, and the extent to which the perianth enlarges and becomes fleshy in fruit. Mr. Colenso made no less than 4 species, based mainly on variations in the above characters, but his own specimens show how inconstant these distinctions are, and how little they can be relied upon.

3.

M. axillaris, Walp. Ann. i. 552.—A small much-branched prostrate or diffuse shrubby plant, usually forming densely matted patches 3–12 in. diam., but sometimes open and straggling; stems and branches woody; branchlets puberulous. Leaves on rather long petioles, small, 1/10–⅓ in. long, broadly oblong or ovate-oblong or almost orbicular, obtuse or retuse, rounded at the base, flat, quite glabrous, dotted beneath. Flowers small, solitary or 2. together in the axils of the leaves, or the males rarely forming short few-flowered spikes at the ends of the branchlets; pedicels slender. Stigmas fimbriate. Perianth succulent in fruit or almost unaltered. Nut triquetrous with obtuse angles, black, smooth and shining, rather longer than the perianth.—Hook. f. Handb. N.Z. Fl. 236; Benth. Fl. Austral. v. 275. M. hypogæa, Col. in Trans. N.Z. Inst. xxi. (1889) 98. Polygonum axillare, Hook. f. Fl. Nov. Zel. i. 211.

North Island: Mountain districts in the interior, from Taupo and the East Cape southwards. South Island: Common in mountain districts throughout. Sea-level to 4500 ft. December–March.

Also found in Tasmania and Australia, and reported from Lord Howe Island.

4.

M. ephedrioides, Hook. f. Fl. Nov. Zel. i. 211.—A much-branched prostrate shrub; stems 9–36 in. long or more, rigid and wiry, deeply grooved, leafless and rush-like or sparingly leafy; page 594branchlets often scaberulous. Leaves when present few and scattered, periolate or almost sessile, ⅙–1 in. long, linear or linear-lanceo-late, often dilated or almost hastate at the base, acute or obtuse, glabrous, sometimes scaberulous on the midrib beneath; stipules short, obliquely truncate. Flowers small, polygamous; those on the male plant in lax axillary simple or branched glabrous spikes, often with a few female flowers intermixed; on the female plant in few-flowered fascicles or short dense spikes, usually with 1 or two male flowers mixed with the females. Stigmas fimbriate. Perianth succulent or remaining unaltered in fruit. Nut exceeding the perianth, black, smooth and shining, triquetrous with the angles obtuse. —Handb. N.Z. Fl. 237.

Var. muricatula.—Smaller and much more slender, branchlets often almost filiform. Leaves usually present, ⅙–½ in. long, linear. Perianth-segments membranous in fruit.—M. muricatula, Col. in Trans. N.Z. Inst. xxii. (1890) 482 (perhaps a distinct species).

North Island: Hawke's Bay—Near the sea, Colenso! A. Hamilton! Upper Rangitikei, Bishop Williams, Petrie! South Island: Marlborough — Near Blenheim, Buchanan! Kirk! Canterbury—Waipara, Haast! Otago—Lower Waitaki, Hector and Buchanan; Kurow, Awamoko, Roxburgh, Petrie! Var. muricatula: North Island—Lake Taupo, Tryon! Ruapehu, H. Hill! Waipawa, A. Hamilton! Sea-level to 3000 ft. December–March.

Easily recognised by the prostrate rush-like stems, which are often entirely leafless.