Art. L.—On the Macrocephalous Olearias ofNew Zealand with Description of a New Species.
[Read before the Wellington Philosophical Society, 13th February 1891.].
Olearia is restricted to New Zealand and Australia, the species of each country being endemic, and exhibiting a remarkable amount of variation in habit, from dwarf shrubs to trees 40ft. high, with solitary, racemose, or paniculate in florescence, some of the forms being of great beauty. The species with large solitary or racemose flower-heads are, however, the most attractive to the cultivator, and possess the greatest amount of interest for the botanist. As the published descriptions of some of the forms included in this section are imperfect owing to paucity of material, it is desirable to revise them when needed, and to state their chief characteristics and their distribution more fully than has hitherto been attempted.
In this section the leaves may be narrow-lanceolate, oblong or ovate, or orbicular-ovate, and are the largest to be found in the genus; their margins may be entire, or sharply serrate or crenate, or doubly serrate or crenate; in several species the teeth are obtuse, rounded, and callous, but in all cases the texture is exceedingly coriaceous; the under-surface, or rarely both surfaces of the leaf, are clothed with appressed white tomentum; and the leaf is either distinctly petioled or narrowed at the base into a flat-winged petiole.
The flower-heads are invariably terminal, although subsequent to flowering their position is often obscured by the elongation of the shoot; they may be solitary or racemose but are never paniculate, and the peduncles may be naked or clothed with linear or imbricating or foliaceous bracts. The
peduncles, rhachis, pedicels, under-surfaces of bracts, and usually the outer involucral leaves, are more or less clothed with appressed snow-white tomentum. Again, the involucral leaves may be arranged in one or two or many series; the outer series of florets may be either ligulate or campanulate, so that the heads are rayless or destitute of rays, while the disc-florets may be yellow or of a deep violet-purple colour; lastly, the achenes may be glabrous or silky, and the pappus-hairs equally arranged in a single series, or unequal and arranged in two series.
A. Flower-heads terminal.
1.Olearia semidentata, Decaisne, in Hook, f., Fl. N.Z., i., 115.
A small sparingly-branched shrub 1ft.—2ft. high; branches slender, sparingly clothed with loose tomentum. Leaves close-set, spreading or ascending, 1½in.—2 ½in. long, ¼in.—⅓in. broad, linear-lanceolate, acute, narrowed at the base, distantly serrate, white beneath, with thin appressed tomentum, coriaceous. Heads crowded on slender peduncles, equalling or exceeding the leaves, and clothed with distant linear bracts; involucral leaves in 3 series, acute. Achenes faintly striate, glabrous or faintly puberulous.
Hab. Chatham Islands: Dieffenbach, Captain Gilbert Mair, W. L. Williams, H. H. Travers, and others.
A charming plant, easily distinguished from all other species by the crowded linear, acute serrate leaves, which are sometimes less than ¼in. broad. The ray-florets are purple, those of the disc deep violet.
2. O. chathamica, n.s.
Of similar habit to the preceding, but more robust. Leaves excessively coriaceous, 1in.—2in. long, ⅓in.—⅔in. broad, ovate, or oblong-lanceolate, narrowed into a short broad petiole, acute, serrate, teeth with obtuse callous tips; white, with appressed tomentum beneath; midrib and lateral nerves prominent beneath. Flower-heads few, on slender peduncles with distant linear bracts, white beneath; involucral leaves in 2 series, the outer white, with loose tomentum; ray-florets with white ligulate corollas, disc-florets violet-purple. Achenes striated pubescent. O. operina, Hook, f., Handbk. N.Z. Fl., p. 731. O. angustifolia, var., J. Buchanan, Trans. N.Z. Inst. vii. (1874), pl. xv.
Hab. Chatham Islands.H. H. Travers!
Best distinguished fromO. semidentata by the broader, coriaceous leaves, with obtuse teeth; fromO. operina andO. angustifolia, by the slender peduncles and distant linear bracts. A charming plant. In the “Vegetation of the Chatham Islands,” under “O.semidentata,” p. 22, Baron von
Mueller, referring to this plant, remarks, “The leaves are not unlike those of O. colensoi”
3. O. operina. Hook, f., Fl. N.Z., i., 115.
A sparingly-branched shrub, 6ft.-12ft. high. Branches stout, loosely tomentose. Leaves very coriaceous, spreading, 2in.—4in. long, white with appressed tomentum beneath, narrowly obovate-Ianceolate, acuminate, narrowed into a winged petiole, teeth close, obtuse, callous; veins obscure beneath. Peduncles 1in.—3in. long, crowded, stout, clothed with short imbricating cottony bracts. Heads large, involucral leaves in 2–3 series, tomentose. Achenes silky. Arnica operina, Forster.
Var. β Branches short, stout; leaves short, excessively coriaceous, with more deeply-toothed margins. Peduncles stouter.
Hab. South Island: Martin's Bay to Preservation Inlet. Sea-level to 100ft. β Preservation Inlet.
It is remarkable that no drawing of this fine plant has been published. The heads are often very numerous, varying from four to eighteen, but more frequently from, six to ten; the rays are white, the disc-florets yellow.
At Puysegur Point an area of several acres was cleared when the lighthouse was erected, and is now covered with dwarf specimens of this species, sparingly intermixed with O. colensoi and O. traillii, the whole presenting a singular appearance owing to the compact strict habit, which is very different from the somewhat straggling habit of ordinary specimens.
4. O. angustifolia, Hook, f., Fl. N.Z., i., 115.
A shrub or small tree, 6ft.-20ft. high, with robust tomentose branches. Leaves 3in.–5in. long, narrow - lanceolate acuminate, narrowed below, sessile, excessively rigid and coriaceous, crenate or doubly crenate or serrate, the points being hard and rounded, white with appressed tomentum beneath, midrib and principal nerves prominent beneath. Heads 1½in.–2in. in diameter on stout peduncles, shorter than the leaves; bracts foliaceous, imbricating, white beneath. Involucral leaves in 2 series, the outer densely tomentose. Ray-florets ligulate, each with a linear scale at its base. Achene silky, grooved. Pappus short, unequal. T. Kirk, Forest Flora of N.Z., t. 138.
Hab. Exposed places by the sea, south of Paterson's Inlet, Stewart Island. Sea-level to 100ft.
The most beautiful species of the genus, and one of the rarest. Flower-heads from 3 to 10; ray-florets white, disc-florets violet-purple. Leaves fragrant. Distinguished
from all other pedunculate species by the narrow rigid foliage and foliaceous bracts.
B. Flowers in Terminal Racemes.
5. O. traillii, T. Kirk, Trans. N.Z. Inst., xvi. (1883), p. 372; Forest Flora of N.Z., t. 142.
A shrub or small tree, 15ft. high or more, with robust tomentose branchlets. Leaves crowded near the tips of the branchlets, 4in.—6in. long, 1in.—1¼in. broad, lanceolate or narrow obovate-lanceolate, acute or acuminate, narrowed into a broad winged petiole, very coriaceous, white beneath, margins doubly crenate with narrow rounded callous points. Heads in erect terminal 3–8 flowered racemes, with foliaceous deciduous bracts; rhachis, peduncles, and under-surface of bracts white with appressed tomentum; peduncles 2in.—8in. long; involucral leaves in 3 series, scarious, acute, the outer sparingly tomentose at the tips; ray-florets ligulate, disc-florets tubular campanulate. Achenes grooved, silky.
Hab. Sea-level, Stewart Island, rare and local.
One of the most striking plants, in the N.Z. flora, easily distinguished from the other racemose species by its narrow leaves and rayed heads. Rays milk-white, disc-florets violet-purple.
6. O. colensoi, Hook. f., Fl. N.Z., 115, t. 29.
Hab. North and South Islands to Stewart Island. Not observed below 3,000ft. in the North Island, but descends to sea-level on Stewart Island. Ascends to 5,000ft.
In the North and South Islands this fine species is confined to the mountains, and is usually a bush or shrub with leaves varying from broadly-oblong to narrow-obovate, but on Stewart Island it descends to the sea-level, and occasionally developes into a tree 40ft. high, with a trunk 2ft. in diameter. The under-surface of the leaves, and the peduncles, are clothed with white appressed hairs, the flower-heads are destitute of rays, and the florets are of a lurid brown colour, approaching black. The leaves are usually crenate or doubly crenate, but occasionally specimens are found in which the margins are doubly serrate, both primary and secondary teeth being extremely acute
O. lyallii, Hook, f., Fl. N.Z., i., 116. Eurybia antarctica, Hook, f., Fl. Antarct., ii., 543.
A shrub or small tree, sometimes nearly 30ft. high, with trunk 2ft. in diameter; branches open, robust, tomentose. Leaves broadly-ovate or orbicular-ovate, abruptly acuminate, excessively rigid and coriaceous, doubly serrate or crenate white with floccose tomentum above, and with appressed
tomentum beneath; petiole short, stout, sheathing at the base. Heads in terminal racemes 4in.-7in. long; rhachis, bracts, peduncles, and outer involucral leaves white with appressed tomentum, involucral leaves in from 5 to 8 series Florets similar to those of O. colensoi, but darker, outer series female, rayless. Achene silky, pappus-hairs in two series, thickened upwards.
Hab. The Snares and the Auckland Islands.
Although this grand plant differs widely from O. colensoi in appearance, it is very closely allied to that species, the chief points of difference being the more open habit, stouter branches, orbicular-ovate leaves, stouter petioles, and especially the many-seriate involucre; but specimens may occasionally be found which approach O. colensoi in habit and foliage. The greyish hue of this plant during the summer and autumn months is most striking, and is due to the upper leaf-surfaces being clothed with tomentum which is of much thinner consistency than that on the lower surfaces. The leaves of O. colensoi are sparingly tomentose on the upper surface of the young leaves, but the tomentum disappears before the leaves are fully developed. In O. lyallii it is more plentiful, and appears to be permanent for the first year. The leaves of O. lyallii are more rigid and coriaceous than those of its near ally, and they are often attacked by a handsome orange-coloured fungus, Uredo oleariæ, Cooke, n.s.
C.Peduncle naked, terminal.
8. O. insignis, Hook, f., Fl. N.Z. ii, 331. Bot. Mag. t.
Hab. South Island: Marlborough, from Awatere southwards to the Conway River. Ascends from sea-level to 4,000ft.
A robust species, of remarkable habit and great beauty, usually forming a low spreading shrub 1ft.—3ft. high, and rarely attaining the extreme height of 8ft. The leaves are crowded at the tips of the branches, and vary greatly in outline from oblong to ovate or narrow-obovate; they are from 3in. to 7in. in length, including the petiole, and from 1in. to 4in. broad, shining above, excessively rigid and coriaceous, but quite entire. They are densely clothed with white tomentum beneath, which becomes tawny or reddish in dried specimens, and sometimes projects beyond the margin, forming a narrow white border; the young leaf is usually clothed above with a thin layer of tomentum, which usually disappears entirely, but in some cases a narrow line is left, presenting the appearance of a marginal nerve, which, however, can be easily scraped away. Peduncles 1–5, tomentose, 6in.—12in. long, as thick as a goosequill, usually naked, but not unfrequently one or several sessile or pedunculate clasping leafy, bracts are
developed, sometimes of irregular shape, at others resembling ordinary leaves, except in size. Head 1in.—2 ½in. diameter, with numerous series of closely-imbricating involucral leaves, which are excessively tomentose, tips acuminate, flat or recurved; in some specimens the basal series is greatly enlarged, forming a kind of spurious involucre. The ray-florets are very numerous, filiform and tubular below, with rather, long flat rays; disc-florets yellow. Achene very long and excessively silky; pappus 1-seriate, hairs thickened upwards, white changing to reddish-brown when dry.
The abnormal development of bracts may partly be caused by external conditions. Three plants which I had under cultivation in pots some years ago produced naked peduncles for two years, but on their roots becoming cramped bracts were freely developed on most of the peduncles. Even in the wild state naked and Bracteate peduncles may be found on the same branch, and it is certain that bracts are more freely developed in some seasons than in others.
Olearia marginata, Colenso, Trans. N.Z. Inst., xv. (1884),. p. 321, appears to be a form of O. insignis, with bracteate peduncles, and the tomentum. produced beyond the margin of the leaves, but I have not seen authenticated specimens of Mr. Colenso's plant. It was found near Renwicktown, Marlborough.
Olearia grandiflora, Hook, f., Ic. Pl, t. 862, from South Australia, and O. pannosa, Hook. f. (Eurybia pannosa, F. Mueller, Pl. Vict., t. 32), from South Australia and Victoria, are nearly allied to O. insignis, Hook, f.
All the species of this section are easily cultivated, and require very little special treatment. They bear cutting-in freely, and are easily propagated by layers and cuttings. They will flourish in any ordinary garden-soil, but attain their greatest luxuriance in a mixture of peat and loam