Page:Manual of the New Zealand Flora.djvu/191

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Myriophyllum.]
HALORAGEÆ.
151

A widely distributed genus of from 15 to 20 species, found in fresh waters in nearly all parts of the world. One of the New Zealand species is endemic, the rest extend to Australia, and one to South America as well.

Leaves whorled; lower pectinately pinnatifid, with capillary segments; upper oblong, entire 1. M. elatinoides.
Leaves whorled; lower pectiuately pinnatifid, with capillary segments; upper linear, entire or serrate 2. M. intermedium.
Leaves whorled, all pectinately pinnatifid. Nuts large, tubercled 3. M. robustum.
Minute, 1–3 in. All the leaves opposite, minute, linearspathulate, entire 4. M. pedunculatum.


1. M. elatinoides, Gaud. in Ann. Sci. Nat. Ser. i. 5 (1825) 105.—Forming dense masses in still waters. Stems slender, 6 in. to 3 ft. long according to the depth of the water. Submerged leaves in whorls of 4:, rarely more, deeply pectinately pinnatifid, the segments capillary; the upper emerged or floral leaves in whorls of 4 or 3, sometimes opposite, much smaller, 1/51/3 in. long, ovate or oblong to broadly lanceolate, sessile, obtuse, entire or the lower slightly toothed. Male flowers: Calyx-lobes very minute. Petals 4, oblong. Stamens 8. Females: Calyx-lobes and petals apparently wanting. Nuts 4, small, oblong, smooth.—Hook. f. Fl. Nov. Zel. i. 63; Handb. N.Z. Fl. 66; Benth. Fl. Austral. ii. 487; Kirk, Students' Fl. 150.

North and South Islands, Stewart Island: Common in rivers and lakes from the Auckland Isthmus southwards, ascending to 3500 ft. November&endash;February. Also in Australia and extra-tropical South America.

Subalpine specimens are stouter, with less delicate and more closely set submerged leaves, and the nuts are rather larger.


2. M. intermedium, D.C. Prodr. iii. 69.—Very variable in habit: in lakes and rivers forming masses of floating stems 1–4 ft. long, with numerous submerged leaves; in wet ground sometimes only an inch or two high, with the leaves all linear and entire. Leaves in whorls of 3–8, usually 4–5; submerged leaves deeply and finely pectinately pinnatifid, segments capillary; upper emerged or floral leaves much smaller, ¼–½ in. long, lanceolate and inciso-pinnatifid to narrow-linear and quite entire. Male flowers: Calyx-lobes evident. Petals white. Stamens 8. Female flowers: Calx-lobes and petals apparently wanting. Nuts 4, very small, linear-oblong, usually minutely scabrid or almost echinate, rarely quite smooth.—M. variæfolium, Hook. f. in Hook. Ic. Plant. t. 289; Fl. Nov. Zel. i. 64; Handb. N.Z. Fl. 66; Benth. Fl. Austral. ii. 487; Kirk, Students Fl. 150. M. propinquum, A. Cunn. Precur. n. 532.

North and South Islands, Stewart Island: Abundant in lakes and streams, wet swamps, &c., from the North Cape southwards, ascending to 3000 ft. December–March. Also in Australia, Malaya, and India.


3. M. robustum. Hook. f. Handb. N.Z. Fl. 67.—Stems stout, erect, branched at the base, 6 in. to 2 ft. high, rarely more. Leaves