30. Ophioglossum, Linn.

Rhizome usually short and suberect, sometimes slightly tuberous or nodose; roots thick and fleshy, simple, sometimes giving rise to adventitious buds. Fronds solitary or 2–3 at the-top of the rhizome, not circinate, stipitate, fleshy, composed of page 1027two portions: one a leafy more or less expanded sterile lamina, with reticulated venation; the other a narrow and much-contracted spike-like fertile part, which is inserted on the petiole or lamina of the sterile portion by a peduncle of variable length. Sporangia closely packed in 2 rows on the fertile spike and partly imbedded in its tissue, globose, not annulate, dehiscing by a transverse slit; spores numerous, tetrahedral.

A small genus, widely spread in both temperate and tropical regions. There is much uncertainty as to the limits of the species, which are estimated by some authors at 8–10, and by others at 30 or more. In the present work I have followed Mr. Baker in treating the New Zealand species as forms only of the northern O. lusitanicum and O. vulgatum; but in Prantl's revision of the genus, given in the Jahrbuch of the Botanical Garden of Berlin for 1884, an arrangement which is now largely followed by European botanists, they are considered to be distinct. Prantl's classification depends largely on characters, drawn from the rhizome, the venation of the sterile frond, and the size of the spores, and is somewhat difficult to use in the absence of authenticated specimens.

Fronds ½–5 in.; sterile lamina ¼–2 in. x ⅛–⅓ in., linear-lanceolate to oblong-lanceolate, attenuated at the base. Fertile spike ¼–¾ in	1. O. lusitanicum.
Fronds 4–10 in.; sterile lamina ¾–3 in. ½-l ½ in., ovate, shortly cuneate at the base. Fertile spike ¾–1 ½ in.	2. O. vulgatum.