150 XXVIII. HALOEAGEAE. [Myriophyllum. 



1-seeded nuts. Embryo terete ; radicle superior. Aquatic or marsh plants, 



with terete sparingly-branched stems, whorled or rarely opposite or alternate 



leaves, which when submerged are divided into capillary segments, the upper 



toothed or pinnatifid or entire. Mowers mostly unisexual, axillary, minute, the 



male usually in the upper axils. 



A widely-distributed genus, comprising about 20 species. One of the New Zealand species is 

 endemic, the others extend to Australia. 



Etym. Prom the Greek, signifying a thousand and a leaf, in reference to the highly-dissected 

 leaves of some species. 



* Flowering -stems subtnerged or aerial. 



Upper leaves whorled or opposite, linear, serrate or pinnatifid . . . . 1. M. intermedium. 



Upper leaves pinnatifid. Stems slender . . . . . . . . . . 2. M. verrucosum. 



Upper leaves whorled or opposite, broad, entire . . . . . . . . S. M. elatinoides. 



** Flowering-stems always aerial. 

 Erect, 9in.-18in. high. Leaves 5, in a whorl .. .. .. ..4. M. rohustum. 



Erect or matted, 2in.-4in. high. Leaves opposite . . .. .. ..5. M. pedunculatum. 



1. M. intermedium, DC, Prod. iii. 69. Stems 6in.-30in. long, accord- 

 ing to the depth of water. Leaves in whorls of 3—8, usually 4—6, those sub- 

 merged pectinately divided into capillary lobes, the aerial floral leaves narrow- 

 linear, entire, serrate, or pinnatifid. j\Iale flowers very shortly pedicelled ; 

 calyx-lobes 4 ; petals white ; stamens 8. Female : calyx-teeth and petals ; 

 carpels 4, smooth. — M. variaefolium, Hook. f. in Hook. Ic. PI. t. 289; Fl. N.Z. 

 i. 65 ; Handbk. 66; A. Cunn., Precurs. n. 532. 



NORTH and SOUTH Islands ; Mongonui to STEWART Island : common in still waters 

 from sea-level to 3,000ft. Dec, Jan. Also in Australia. 



Owing to the evaporation of the shallow winter ponds in which it often grows, this species is 

 sometimes terrestrial, when the uppermost leaves are reduced to a few opposite pairs, linear and 

 quite entire, 



2. M. verrucosum, Lindl. in Mitch. Trop. Austr. 384. Stems slender, 

 12in.— 18in. long. Leaves 3 or 4 in a whorl, the submerged pectinately divided 

 into short capillary segments ; the aerial floral leaves sessile, oblong or lanceo- 

 late, pinnatifid ; lobes short. " Calyx-lobes short, but perceptible in both 

 sexes, very deciduous in the females. Petals in the male under 1 line long. 

 Stamens 8. Females without petals. Styles 4, very short. Carpels 4, rarely 

 above i line long, obtuse on the back, more or less tuberculate." — Benth., 

 Fl. Austr. ii. 488. 



NORTH Island : in ponds near Tauranga, T. K. April, 1865. 



The identification must be considered open to doubt, as the flowers have not been seen, and 

 the fruiting specimens collected by me are very imperfect. Dr. Berggren, who saw the plant 

 growing, agrees with me in the identification. 



3. M. elatinoides, Gaudich. in Ann. Sc. Nat. Ser. I. v. (18,25) 105. 

 Stems 6in.-30in. long. Leaves 4 in a whorl, rarely more, the submerged 

 pectinately pinnatifid ; segments capillary. Flowers in a leafy spike or panicle, 

 2in.-6in. long. Floral leaves in whorls of 4 or 3, those of the male flowers 

 opposite, broadly lanceolate or ovate-lanceolate, entire or toothed. Male ; 



