Manual of the New Zealand Flora/Portulaceæ
Order VII. PORTULACEÆ.
Herbs, usually fleshy and glabrous, occasionally clothed with long hairs. Leaves opposite or rarely alternate, entire, generally exstipulate. Flowers regular, hermaphrodite. Sepals 2, rarely more, imbricate. Petals 4–5, hypogynous or rarely perigynous, free or united below. Stamens either equal in number to the petals and opposite to them or indefinite, often adnate to the base of the petals. Ovary free or rarely half-inferior, 1-celled; style 3–8-fid; ovules few or many, affixed to a free central or basal placenta. Fruit a capsule, either dehiscing with as many valves as style-branches, or opening by a transverse lid. Seeds 1 to many; embryo curved round a farinaceous albumen.
A small order, having its headquarters in America; found more sparingly in South Africa and Australia; decidedly rare in Asia, north Africa, and Europe. Genera 16; species about 125. Some of the American genera are shrubby; and the widely distributed Portulaca (naturalised in New Zealand) differs from the rest of the order in having perigynous petals and stamens, and a half inferior ovary. Of the New Zealand genera, Hectorella is endemic, Claytonia is mainly American, and Montia occurs in the temperate regions of both hemispheres.
|Stems slender. Stamens 5, opposite the petals. Capsule 3–many-seeded, seeds shining||1. Claytonia.|
|Stems slender. Stamens usually 3, opposite the petals. Capsule 1–3-seeded, seeds dull and opaque||2. Montia.|
|Alpine herb with densely tufted stems. Stamens 5, alternate with the petals||3. Hectorella.|
1. CLAYTONIA Linn.
Annual or perennial low-growing glabrous and succulent herbs. Radical leaves petiolate, cauline opposite or alternate. Flowers solitary or in terminal or axillary racemes or cymes. Sepals 2, persistent. Petals 5, hypogynous. Stamens 5, adhering to the petals at the base. Ovary free; ovules few; style 3-cleft. Capsule globose or ovoid, membranous, 3-valved. Seeds reniform or orbicular, flattened.
Species about 20, all from North America or north-eastern Asia with the exception of the following one, which is confined to Australia and New Zealand.
1. C. australasica, Hook. f. in Hook. Ic. Plant. t. 293.—A perfectly glabrous tender and succulent usually matted plant, with slender creeping stems 1–6 in. long. Leaves very variable in size, 1⁄4–11⁄2 in. long, alternate or in distant pairs, narrow-linear or linear-spathulate, obtuse, dilated into broad membranous sheaths at the base. Flowers large, 1⁄4–1⁄2 in. diam., white or rose, terminal or leaf-opposed, solitary or in few-flowered lax racemes; pedicels long, slender. Sepals small, broadly orbicular. Petals much longer, broad-obovate. Capsule globose, mucronate, usually slightly exceeding the sepals. Seeds generally 3, black, smooth and shining.—Fl. Nov. Zel. i. 73; Handb. N.Z. Fl. 26; Benth. Fl. Austral. i. 177; Kirk, Students' Fl. 65.
North Island: Ruahine Range and Ruapehu, H. Hill! Petrie! E. W. Andrews; Mount Egmont, Buchanan, T. F. C. South Island and Stewart Island: Common in mountain districts throughout. Ascends to over 6000 ft. on Mount Egmont, and descends to sea-level in Otago and Stewart Island.
A variable plant. When growing in dry or exposed places it is often very small and densely tufted ; but in watery situations the stems lengthen out considerably and the leaves become longer. Mr. Buchanan (Trans. N.Z. Inst. iii. 210) has described two varieties characterized by the peduncles in one being 2-flowered, and in the other racemose; but I find the number of flowers to be very inconstant.
2. MONTIA, Linn.
A small glabrous herb. Leaves opposite, slightly fleshy. Flowers small, axillary or shortly racemose. Sepals 2, ovate, persistent. Petals 5, united at the base into a 5-lobed corolla, split open on one side. Stamens 3, rarely 5, inserted on the petals. Ovary free; ovules 3. Capsule globose, 3-valved, 3-seeded. Seeds early orbicular.
A monotypic genus, widely distributed in the north and south temperate zones.
1. M. fontana, Linn. Sp. Plant. 87.—A slender perfectly glabrous branching herb, forming dense tufts 1–5 in. high, sometimes longer and weaker when growing in water. Leaves opposite, 1⁄4–1 in. long, linear-lanceolate or spathulate, acute or subacute, quite entire. Flowers minute, solitary or in 2–3-flowered racemes, drooping. Petals slightly longer than the sepals. Capsules small.—Hook. f. Fl. Antarct. 13; Fl. Nov. Zel. i. 74; Handb. N.Z. Fl. 27; Kirk, Students' Fl. 65.
North and South Islands, Stewart Island, Auckland, Campbell, Antipodes, and Macquarie Islands: Abundant in watery places, from Rotorua and Taranaki southwards. Altitudinal range from sea-level to 4000 ft.
3. HECTORELLA, Hook. f
A small densely tufted glabrous perennial. Leaves small, densely imbricated, coriaceous, entire. Flowers almost sessile amongst the uppermost leaves. Sepals 2, short, truncate. Petals 5, connate at the base, thickened below the tip. Stamens 5, inserted on the tube of the corolla, and alternate with the petals; anthers linear-oblong. Ovary free; ovules 4–5, erect from the base of the cell; funicles slender; style erect; stigmas 1–3, linear, papillose. Capsule membranous, equalling the sepals; seeds 2–4.
A monotypic genus confined to New Zealand; not closely allied to any other.
1. H. cæspitosa, Hook. f Handb. N.Z. Fl. 27.—Stems short, stout, densely tufted, with the leaves on almost as thick as the little finger, forming compact rounded cushions 2–8 in. diam. and 1–3 in. high. Leaves very numerous, closely imbricated in many series, 1⁄6–1⁄3 in. long, broadly triangular-ovate to linear-oblong with a broad base, thin and membranous below the middle, coriaceous and keeled above; margins and tip thickened; veins reticulated. Flowers small, white, very shortly peduncled, forming a ring round the top of the branches among the uppermost leaves, often unisexual, the staminate ones being the smallest. Sepals concave, keeled. Petals much longer than the sepals. Capsule globose, membranous, as long as the sepals. Seeds 2–4, broadly ovoid, smooth and shining.—Hook. f. in Hook. Ic. Plant. t. 1046; Kirk, Students' Fl. 65. H. elongata, Buch. in Trans. N.Z. Inst. xvi. (1884) 395, t. 35.
South Island: Canterbury—Mountains above Arthur's Pass, T. F. C.; Mount Cook district, F. G. Gibbs, T. F. C. Otago—Mount Alta; Mount Aspiring, Hector and Buchanan! Hector Mountains, Dunstan Mountains, and all high mountains west of the Clutha River, Petrie! Altitudinal range from 4000 to 6500 ft.
Mr. Buchanan's H. elongata, based on more laxly branched specimens with longer linear-oblong leaves, looks different at first sight, but (as Mr. Kirk has remarked) is connected with the typical state by numerous transitional forms.