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 spikes 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.
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.
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 ovate, 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.