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Manual of the New Zealand Flora.
5. LepilÆna, J. Drummond
5. LepilÆna, J. Drummond.
Very slender submerged water-plants; stems filiform, branched. Leaves alternate or the floral ones opposite, filiform, sheathing at the base; sheaths broad, stipular. Flowers minute, axillary, diœcious or rarely monœcious, solitary within the dilated sheathing bases of a pair of floral leaves. Male flowers shortly pedicelled. Perianth very minute, of 3 hyaline scales. Anthers 2 or 3, united by their backs and forming a solid column resembling a single anther; each anther 2-celled, dehiscing longitudinally. Female flowers sessile or shortly pedicellate. Perianth of 3 hyaline segments longer or shorter than the carpels. Carpels 3, distinct, sessile or shortly stipitate, narrowed into a short or long style; stigma oblong or spathulate; ovule solitary, pendulous. Ripe carpels usually 3, oblong, coriaceous, indehiscent, tipped by the persistent style. Seed oblong; testa membranous; embryo with a thick obtuse radicle and tapering involute cotyledonary end.
A small genus of 4 species, 3 of which are Australian, one of them said to extend to New Zealand; the remaining one is endemic in New Zealand. In Engler's "Naturlichen Pflanzenfamilien" the genus is merged with the Mediterranean Althenia.
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Leaf-sheaths narrow. Anthers 3, connate into a column. Stigma oblong-clavate 1. L. Preissii. Leaf-sheaths broad. Anthers 2 (or 1?). Stigma very large, flat, deeply fimbriate 2. L. bilocularis.
| 1. | L. Preissii, F. Muell. Fragm. Phyt. Austral. viii. 217.—Stems 6–18 in. long, very slender, filiform, branched, often forming dense masses. Leaves filiform or almost capillary; sheathing bases very narrow. Flowers diœcious; males solitary within the leaf-sheaths, shortly pedicelled. Perianth minute, cupular. Anthers 3, sessile within the perianth, connate by their backs into a columnar mass, each one 2-celled, cells dehiscing longitudinally. Female flowers solitary, shortly pedicelled. Perianth of 3 distinct segments, rather longer than the carpels. Carpels 3, narrowed into a rather long style; stigma oblong-clavate. Ripe carpels cylindrical, sessile or nearly so, about ½ in. long.—Benth. Fl. Austral. vii. 180; Kirk in Trans. N.Z. Inst. x. (1878) App. xl., and xxviii. (1896) 199. Zannichellia Preissii, Lehm. in Plant. Preiss. ii. 3.
North Island: Auckland—Waikato River, near Churchill, Kirk. I have seen no New Zealand specimens of this, but according to Mr. Kirk examples collected by him in the locality quoted above were submitted to the late Baron Mueller and by him identified with the Australian L. Preissii. It greatly resembles Zannichellia palustris, and in the absence of male flowers may have been mistaken for it. |
| 2. | L. bilocularis, T. Kirk in Trans. N.Z. Inst, xxviii. (1896) 500.—Stems filiform, much branched, 3–12 in. long. Leaves very narrow-linear or filiform, flat, 1-nerved, obtuse; base broad, expanded into a membranous sheath. Flowers very minute, solitary, diœcious, concealed in the leaf-sheaths. In the male plant the sheathing bases of the floral leaves are broad and much expanded, and conspicuously 2-lobed at the tip. Flowers very shortly pedi-celled. Perianth of 3 most minute hyaline scales. Anthers apparently 2, cohering by their backs and resembling a single anther, each 2-celled, longitudinally dehiscent, connective produced. Floral leaves subtending the female flowers with narrower sheaths; flowers sessile or very shortly pedicelled. Perianth-segments 3, oblong, entire or 2-lobed, almost as long as the styles. Carpels 3, sessile; styles slender; stigmas very large and broad, deeply fimbriate or laciniate. Ripe carpels about 1/15 in. long, slightly oblique, turgid, rounded on the back; style almost as long as the carpel.
South Island: Canterbury—Streams flowing into the Selwyn River; near the outlet of Lake Ellesmere, Kirk! Otago—Lake Waihola, Waikouaiti, Taieri Plain, Petrie! A very curious little plant. Mr. Kirk describes the anthers as solitary; but in Mr. Petrie's Lake Waihola specimens, which are the only males that I have seen, I make the anthers to be 2, placed back to back, but closely resembling a single 4-celled anther. At the same time it is not easy to satisfy one's-self as to the structure of the anther from an examination of dried specimens. |