A HISTORY OF HERTFORDSHIRE Athyrium filix-foemina, Roth Lastrea oreopteris, Presl Polystichum aculeatum, Roth Polypodium vulgare, L. lobatum, Sm. OPHIOGLOSSACE/E angulare, Presl Ophioglossum vulgatum, L. Lastrea filix-mas, Presl spinulosa, Presl MARSILEACE/E dilatata, Presl Pilularia globulifera, L. The more marked varieties which have been found are Scohpendrium vulgare, var. multifidum, in the Lea district ; Athyrium Jilix-fcemma, var. convexum, in the Colne and Lea ; and Polypodium vulgare, vars. acutum and serratum, in the Lea. The earliest county record is in Gerard's Herball (1597) : ' Nicholas Belson founde [a dwarf form of Scolopendrium vu/gare] in a gravellie lane in the way leading to Oxey parke neere unto Watforde, fifteene miles from London.' In 1737 John Blackstone recorded Asplenium adiantum-nigrum and Ophioglossum vulgatum as found near Harefield ; and in 1805 Thomas Woodward recorded Ceteracb officinale as occurring at Ashridge. The next additions, to the number of eleven, were made in 1838 by the Rev. W. H. Coleman. THE HORSETAILS (Equisetacea) Of the only genus of this order, Equisetum, the following species occur in Hertfordshire : E. arvense, L. ; E. maximum, Lamk. ; E. silvaticum, L. ; E. palustre, L. ; and E. limosum, L. Equisetum arvense and limosum occur in all the districts, and E. palustre has been recorded from all but the Brent. E. silvaticum is our rarest horsetail. It is known to have occurred on Hitchin Common in the Ivel district from a single record, and it is somewhat plentiful in two woods in the Lea district Bayford Wood and Bell Wood. All the species were first recorded by Coleman in 1838. THE CLUBMOSSES (Lycopodiacea) Of the three genera of this order, Lycopodium, Selaginella, and Isoefes, the first only is represented in Hertfordshire, and by only a single species, Lycopodium clavatum, L., which has been found in the Colne district near Tring and in the Lea in Broxbourne Wood, Pamplin being the first to record it, in 1837. The rare L. inundatum occurs on Harefield Common, just outside our county boundary. THE MOSSES (Musct) Although the mosses of the county have not been so carefully in- vestigated as the flowering plants and ferns, they have not been neglected. As early as the year 1843 the Revs. W. H. Coleman and R. H. Webb printed in pamphlet form, A Report of the Progress made in the In- vestigation of the Flora of Hertfordshire, with a Catalogue of Species known or reported to have been found. In this catalogue 1 1 8 species 62
