Ophioglossum L.
Sporangia coriac., in two close rows on unbranched axis, globose, opening transversely. Roots slender to rather thick, often proliferating, on erect fleshy to tuberous rhizome. Sterile seg. with a simple, entire lamina; fertile seg. spike-like, rarely branched. Adder's tongue. Genus widespread, the spp. very imperfectly understood.
Our knowledge of the N.Z. forms is superficial, and the grouping into spp. merely conventional. An adequate treatment must await detailed field and laboratory studies. A. Cunningham in Compan. bot. Mag. 2, 1837, 361, described:
(1) O. coriaceum from specimens collected "near the village Matauri, opposite the Cavallo Islands", and (2) O. elongatum (R. C. MSS.) from specimens found "between the Waimate and Keri-Keri Rivers".
Hooker, Fl. N.Z. 2, 1855, 50, placed all his N.Z. material under O. vulgatum L., but recognized as vars: var. ß costatum - O. costatum R. Br., O. elongatum R. Cunn.; var. γ gramineum - O. gramineum Willd.; var. δ Lusitanicum - O. lusitanicum Auct.; O. coriaceum A. Cunn.; var. ε minimum. His distinguishing characters are:
(a) var. costatum -fronde ovata v. lanceolata reticulatim venosa costata v. ecostata.
(b) var. gramineum -fronde ovata v. lanceolata acuta ecostata enervi.
(c) var. Lusitanicum -fronde lineari-lanceolata v. lineari-oblonga enervi ecostata.
(d) var. minimum -parvulum, 1-2-unciale, fronde rhombeo-ovata v. oblonga acuta.
No definite localities are cited by Hooker.
Armstrong, T.N.Z.I. 13, 1881, 342, described his O. minimum from plants collected on the "Canterbury Plains, near Christchurch; rare." His description includes: "barren [fronds] 1/2-1 inch long, ovate, acute, closely appressed to the ground, usually in pairs . . . Costa 0. Veins obsolete or faintly reticulated. Fertile frond less than 1 inch high, spike-like, very narrow, with 10-24 capsules in two rows."
Thomson, Ferns and Fern Allies of N.Z., 1882., 98, recognized two spp.: O. Lusitanicum L. (O. coriaceum A. Cunn.)-"rootstock slightly tuberous. Frond 1-3 in. long"; O. vulgatum L. (O. elongatum A. Cunn.) "rootstock not tuberous. Frond 3-12 in. long".
Cheeseman, Man. N.Z. Fl. 1925, 93, recognized Cunningham's two spp., but referred O. elongatum to O. pedunculosum Desv. in Berl. Mag. 5, 1811, 306. In essence his treatment is:
