Manual of the New Zealand Flora.

11. Gahnia, Forst

11. Gahnia, Forst.

Tufted perennial herbs, usually of large size. Stems tall and stout, leafy throughout; their length. Leaves usually long, very coarse and harsh, narrowed into long subulate or filiform points; margins involute, scabrid. Panicle large, terminal; sometimes broad and effuse, with drooping branches; sometimes narrower and more erect. Spikelets clustered, black or dark-brown, 1–2-flowered; the upper flower hermaphrodite and fruit-bearing; the lower flower sterile or male. Glumes many, imbricated all round; the outer 2–5 or more empty, keeled, often mucronate; flowering glumes minute at first, but enlarging in fruit. Hypogynous bristles wanting. Stamens usually 4 in the hermaphrodite flower, often 4–6 in the male flower; filaments greatly elongated after flowering, and often holding the nut. Nut hard and bony, ellipsoid or ovoid or obovoid, obscurely trigonous or terete, red or reddish-brown or black.

Species about 30, most of them natives of Australia and New Zealand, but extending through the Pacific islands to the Sandwich Islands and Malay Archipelago. Of the 8 found in New Zealand, one occurs in Lord Howe Island and another in the Sandwich Islands, the remaining 6 are endemic. The genus is remarkable for the extraordinary extent to which the filaments lengthen after flowering. In G. procera they are often quite 2 in. long, or from 8 to 10 times the length of the flowering glumes. They generally remain attached to the base of the nut after it has fallen away, and as the other end of the filament is usually entangled with the glumes or with the filaments of other flowers the nut remains swinging by the filaments quite free from the spikelet. Mr. Colenso (Trans. N.Z. Inst. xviii. 281) has suggested that some of these filaments are in reality hypogynous scales, giving as a reason for this belief that in his G. scaberula and G. exigua he has noticed within the same flower stamens with the filaments still very short, and filaments already lengthened to the full extent. He failed to notice that the lower male flower expands long before the hermaphrodite flower placed just above it, so that its filaments have lost their anthers and lengthened long before the expansion of the upper flower takes place. The two flowers are placed so close together that it is quite easy to take the two for one.

Tall, 3–7 ft. Panicle 1–3 ft., nodding. Glumes 7–8; 4–5 empty, unequal. Nut small, ⅙ in., red-brown 1. G. setifolia.
Smaller, 2–4 ft. Panicle 1½–2½ ft., rigid, erect. Glumes 6–7; 3–4 empty, subequal. Nut small, ⅙ in., red-brown 2. G. rigida.
Slender, 2–4 ft. Panicle 1½–2½ ft., narrow, elongate, branches distant. Glumes 8; 5 empty, unequal. Fruit large, ⅕–¼ in., red-brown 3. G. pauciflora.
Very tall and stout, 5–12 ft. Panicle 2–5 ft., nodding.
Glumes 6–7; 4–5 empty, subequal. Nut large, ⅕–¼ in., black when fully ripe 4. G. xanthocarpa.
Tall and stout, 5–7 ft. Panicle 2–3 ft., rigid, erect, Glumes 8; 5 empty, subequal. Nut small, ⅙ in., black 5. G. robusta. Leafy, 2–4 ft. Panicle 1–1½ ft., narrow, lax. Glumes 4; 2 empty, very long. Nut large, ¼ in., red-brown 6. G. procera.
Slender, 2–4 ft. Panicle 9–18 in., slender, narrow but dense. Glumes 4–5; 2–3 empty. Nut small, ⅙in., black 7. G. lacera.
Small, 6–14 in. Leaves exceeding the stem, spreading.
Glumes 6; 4 empty. Nut small, ovoid, apiculate, black 8. G. Gaudichaudi.
1. G. setifolia, Hook. f. Fl. Nov. Zel. i. 278.—Stems numerous, tall, stout, 3–7 ft. high, forming large tussocks. Leaves many, almost as long as the stems, involute, with scabrid cutting edges and long filiform points. Panicle large, nodding, 1–3 ft. long, much and laxly branched; branches long, erect in flower, drooping in fruit; bracts long and leafy, with scabrid filiform points. Spikelets very numerous, dark-brown or almost black, ⅙–⅕ in. long, 2-flowered; the lower flower male, the upper hermaphrodite and fruit-bearing. Glumes 7–8; the 4–5 outer ones empty, gradually increasing in length, keeled, acuminate, minutely scaberulous; the 3 upper very small at the time of flowering and concealed within the uppermost empty glume, enlarged in fruit and closely appressed to the nut, obtuse, convolute. Stamens usually 4 to each flower, but varying from 4 to 6; filaments greatly elongated in fruit. Style-branches 3, rarely 4. Nut small, ⅙ in. long, elliptic-obovoid, narrowed at both ends, smooth and shining, indistinctly grooved, red-brown when fully ripe, transversely grooved within.— Handb. N.Z. Fl. 306. G. scaberula, G. parviflora, and G. multiglumis, Col. in Trans. N.Z. Inst. xviii. (1886) 278–80. Lampocarya setifolia, A. Rich. Fl. Nouv. Zel. 111; A. Cunn. Precur. n. 282; Raoul, Choix, 40. North Island: Abundant throughout. South Island: Marlborough—Picton, J. Rutland! Sea-level to 2000 ft. December–January.
2. G. rigida, T. Kirk in Trans. N.Z. Inst. ix. (1877) 551.—Stems densely tufted, harsh and rigid, erect, 2–4 ft. high. Leaves equalling the stems, with involute scabrid margins and very long drooping filiform points. Panicle stiff, erect, rather narrow, elongate, 1½–2½ ft. long; branches numerous, short, strict, erect; bracts with dark sheaths and long filiform points. Spikelets numerous, crowded, dark-brown or almost black, ⅕–¼ in. long, 2-flowered; the lower flower male, the upper hermaphrodite and fruit-bearing. Glumes 6–7; the 3–4 outer empty, almost equal in length, keeled, narrowed into long acuminate points, scaberulous on the keel, margins paler, membranous; the 3 inner small at the time of flowering, enlarged in fruit, convolute, obtuse. Stamens 4–5 in each flower; filaments greatly elongated in fruit. Style-branches 3. Nut small, ⅙ in. long, oblong-obovoid, smooth, brown, or brown mottled with red and black.—G. exigua, Col. in Trans. N.Z. Inst. xviii. (1886) 279. South Island: Nelson—Dun Mountain, T. F. C.; Aorere Valley and Nga-kawau, Kirk; Westport, Townson! Westland—Between Hokitika and Ross, Marsden, near Greymouth, Kirk! Sea-level to 2500 ft. Distinguished from G. setifolia by the usually smaller size, erect rigid panicle, longer and more acuminate subequal glumes, and more obovoid nut. The erect compact panicle, subequal glumes, and small nut separate it from the following species.
3. G. pauciflora, T. Kirk in Trans. N.Z. Inst. i. ed. 2 (1871) 94.—Stems slender, sparingly leafy, 2–3 ft. high, rarely more. Leaves equalling the stems, narrow, with scabrid cutting edges and long filiform points. Panicle long, lax but narrow, 1½–3 ft. long; branches distant, slender; bracts long, leafy. Spikelets loosely scattered on the branches of the panicle, not crowded, sessile or shortly pedicelled, brownish-black, ⅕–¼ in. long, 2-flowered; lower flower male, upper hermaphrodite and fruit-bearing. Glumes usually 8; the 5 lower ones empty, gradually increasing in size, ovate, acute or acuminate; the 3 upper small at first, but enlarging in fruit, deeply concave, appressed to the nut, obtuse. Stamens 4–5 to each flower; filaments greatly elongated in fruit. Style-branches 3–4. Nut large, ⅕–¼ in. long, elliptic-ovoid, acute at both ends, smooth and shining, often grooved on the inner face, red-brown with a dark tip, transversely grooved within.—G. Hectori, Kirk in Trans. N.Z. Inst. ix. (1877) 551. North and South Islands: From the North Cape southwards to Marlborough, Nelson, and Westland, plentiful. Sea-level to 3000 ft. October–December. A well-marked species, at once recognised by the slender elongated panicle, with lax distant branches; the numerous empty glumes, the lower of which are unusually small; and the large red-brown nut.
4. G. xanthocarpa, Hook. f. Handb. N.Z. Fl. 306.—Stems numerous, stout, often as thick as the finger, densely tufted, leafy, 5–12 ft. high, forming huge clumps in forests. Leaves numerous, very long, ½ in. broad or more, involute, scabrid on the margins and veins, upper part produced into long filiform points. Panicle very large, 2–5 ft. long, drooping, excessively branched; branches long, slender, pendulous, 9–18 in. long or even more; bracts long, leafy. Spikelets innumerable, densely crowded, brown, ⅕–¼ in. long, 2-flowered; lower flower male, upper flower hermaphrodite and fruit-bearing. Glumes 6–7; the 3–4 outer empty, not very different in length, ovate, shortly acuminate; the 3 upper smaller, deeply concave, obtuse. Stamens usually 4 to each flower; filaments lengthening much in fruit. Style-branches 3–4. Nut large, ⅕–¼ in. long, elliptic-oblong or-obovoid, acute at both ends, smooth and shining, sometimes indistinctly grooved, black when fully ripe, yellowish when immature, transversely grooved within.— Benth. Fl. Austral. vii. 418. G. ebenocarpa, Hook. f. ex Kirk in Trans. N. Z. Inst. i. (1869) 149. Lampocarya xanthocarpa, Hook. f. Fl. Nov. Zel. i. 278. Cladium xanthocarpum, F. Muell. Fragm. Phyt. Austral. ix. 13. North Island: Not uncommon in forests throughout. South Island: Marlborough— J. Rutland! Nelson—Motueka Valley, T. F. C.; Westport, Townson! Westland—Hokitika, Kirk! Canterbury— Haast, Armstrong. Sea-level to 2500 ft. February–March. The finest species of the genus, at once identified by its large size, enormous panicles, and large black nut. Also recorded from Lord Howe Island.
5. G. robusta, T. Kirk in Trans. N.Z. Inst. xxvi. (1894) 261.—Stems robust, as thick as the little finger, 6–7 ft. high. Leaves almost as long as the stems, involute, with scabrid margins and long filiform points. Panicle large, 2–3 ft. long, dense, narrow, erect; branches 5–10 in. long, strict, erect; bracts leafy, with long filiform points. Spikelets crowded, dark-brown or almost black, 2-flowered; lower flower male, upper hermaphrodite and fruitbearing. Glumes usually 7; the 4 outer empty, subequal, awned; the 3 inner small in the flowering stage, but enlarged in fruit, concave, coriaceous, obtuse. Stamens 4–6 in each flower, elongated in fruit. Style-branches 2–4. Nut small, ⅙–⅕ in. long, elliptic-obovoid, black when fully ripe, transversely grooved within. North Island: Wellington—Mungaroa, Kirk! March. My knowledge of this plant is confined to the specimens in Mr. Kirks herbarium. These greatly resemble G. rigida, but the plant is said to be much larger, and the nut to be always black when fully ripe.
6. G. procera, Forst. Char. Gen. 52.—Stems stout, densely tufted, 2–4 ft. high. Leaves equalling or exceeding the stems, narrowed into long filiform points; margins involute, smooth below, scabrid above; sheaths dark-brown or almost black. Panicle slender, lax but narrow, elongate, 12–18 in. long; branches often remote, short, erect or slightly drooping in fruit; bracts leafy, with purplish-black sheaths. Spikelets scattered along the branches or clustered towards their tips, large, ⅓–½ in. long, dark purplish-black, 2-flowered; lower flower male, upper hermaphrodite and fruit-bearing. Glumes 4; 2 outer empty, very large and exceeding the spikelet, elliptic-lanceolate, mucronate, striate; 2 inner shorter, oblong-lanceolate, obtuse. Stamens usually 4 to each flower; filaments elongating greatly in fruit. Style-branches 4. Nut large, ¼ in. long, narrow-elliptic, smooth and shining, obscurely grooved, reddish-brown or reddish-yellow when ripe, transversely grooved within.— A. Rich. Fl. Nouv. Zel. 112; A. Cunn. Precur. n. 284; Raoul, Choix, 40; Hook. f. Fl. Nov. Zel. i. 278; Handb. N.Z. Fl. 306. South Island: Nelson—Buller Valley, T. F. C.; Mount Rochfort and vicinity of Westport, Townson! Westland—Hokitika, Kirk! Kelly's Hill, Cockayne! Otago—Dusky Sound, Forster; Port Preservation, Lyall; Clinton Valley, Petrie. Stewart Island: Port Pegasus, Petrie! Pearson! Sea-level to 2500 ft. December–February. A very distinct species, remarkable for the large purplish-black spikelets and long empty glumes, which are only 2 in number. There is an unnamed specimen, presumably from the North Island, in Mr. Colenso's herbarium.
7. G. lacera, Steud. Cyp. 164.—Stems rather slender, leafy, densely tufted, 2–4 ft. high. Leaves equalling or exceeding the stems, flat or involute, ⅓–½ in. broad, narrowed into long filiform points, margins scabrid. Panicle elongated, narrow but rather dense, 9–18 in. long; branches short, erect or inclined; bracts long and leafy. Spikelets alternate on the branches of the panicle, shortly pedicelled, brown, 1-flowered. Glumes 4–5; 2 or 3 outer empty, subequal, ovate or ovate-lanceolate, acuminate or awned, rather membranous, minutely scaberulous on the back; 2 inner shorter, concave, obtuse, margins scarious and lacerate. Stamens 4; filaments greatly elongate in fruit. Style-branches 3. Nut small, ⅙ in. long, oblong-obovoid, obtuse, shining, black, very obscurely transversely striate within.— Hook. f. Handb. N.Z. Fl. 306. Lampocarya lacera, A. Rich. Fl. Nouv. Zel. 109; A. Cunn. Precur. n. 281; Raoul, Choix, 40; Hook. f. Fl. Nov. Zel. i. 277. North Island: From the North Cape to Cook Strait, not uncommon. Sea-level to 2000 ft. July–August. This is quoted from the South Island in the Handbook, but I have seen no specimens from thence.
8. G. Gaudichaudii, Steud. Cyp. 164.—Stems short, densely tufted, obtusely trigonous, leafy, 6–18 in. high. Leaves very numerous, spreading, much exceeding the stems, narrow, rigid, scabrid, sheaths short, submembranous. Panicle narrow, contracted, rigid, leafy, 3–9 in. long; branches few, short, erect; bracts very long and leafy. Spikelets clustered on the branches, ellipticlanceolate, turgid, acute, chestnut-brown, 1-flowered. Glumes 6, firm, and coriaceous, minutely puberulous, ciliolate on the margins; 4 outer small, gradually increasing in size, ovate-lanceolate, acuminate, awned; 2 inner much longer, rigid in fruit, acuminate. Stamens usually 3; filaments scarcely lengthening after flowering. Style-branches 3. Nut small, ovoid, obscurely trigonous, minutely apiculate, smooth, black, not transversely grooved within.— Hillebr. Fl. Hawaii, 481. G. affinis, Steud. Cyp. 164. G. arenaria, Hook. f. Handb. N.Z. Fl. 306. Lampocarya affinis, Brong. in Duperr. Voy. Coq. Bot. 166, t. 29; Hook. f. Fl. Nov. Zel. i. 277. Morelotia gahniæformis, Gaud. in Freyc. Voy. Bot. 416, t. 28; A. Rich. Fl. Nouv. Zel. 115; A. Cunn. Precur. n. 285; Raoul, Choix, 40. North and South Islands: Dry hills from the North Cape to Banks Peninsula, but not common to the south of Cook Strait. Sea-level to 2000 ft. Also in the Sandwich Islands.