A Flora of Southern Illinois

Division Pterdophyta

Division Pteridophyta 1. Lycopodiaceae - Clubmoss Family Lycopodium L. 1. Stems erect; sporangia not in terminal cones 2 2. Leaves entire . . Lycopodium lucidulum" 2. Leaves minutely toothed . .Lycopodium lucidulum var. occidentale 1. Stems creeping; sporophylls in terminal cones Lycopodium complanatum var. flabelliforme" Lycopodium lucidulum Michx. (1:3 ). The typical species is known from a moist sandstone ravine at Jackson Hollow in Pope County. Variety occidentale (Clute) L. R. Wilson is known only from one station in Illinois, a wet north-facing bluff with slightly acid soil, in Little Grand Canyon, Jackson County. Lycopodium complanatum L. var. fiabelliforme Fern. (Fig. 1) has been found once in Illinois (J. R. Swayne 2328 in 1952). It occurs along a rugged sandstone bluff overFIG . 1. Trailing Ground-Pine (Lycopodium complanatum var. flabelliforme), a distinctly northern species, occurs at Indian Kitchen on Lusk Creek. It is near the southernmost limit of its range. FIG. 2. Lusk Creek has cut deeply through Pennsylvania sandstone in Pope County. The stream is viewed from about one hundred feet above the water at a point known locally as Indian Kitchen. 42 2. SELAGINELLACEAE-SMALL CLUBMOSS FAMILY looking Lusk Creek in Pope County (Fig. 2). SP. CIT.: (L. lucidulum var. occidentale), Little Grand Canyon, November 22,1949, Hatcher. 2. Selaginellaceae - Small Clubmoss Family Selaginella BEAUV. 1. Leaves delicate, not bristle-tipped; plants of moist situations . Selaginella apoda " 1. Leaves firm, bristle-tipped; plants of dry exposed places Selaginella rupestris " Although no species of Selaginella has been collected in Jackson County, two are to be looked for. Selaginella apoda (L.) Spreng. ( 1: 9) occurs along streams or in rich woods and has been collected in Union and Pope counties. Selaginella rupestris (L.) Spreng. (1:9) occurs on bare sandstone blufftops in Pope County. Jones et al. (1955) attribute Selaginella apoda to Jackson County, but we have seen no specimens. The report may be based on a collection by Hatcher near Alto Pass, which is actually in Union County. 3. Isoetaceae - Quillwort Family 1. Leaves usually about 15 in number, rarely more than 20 cm. tall . Isoetes butleri 1. Leaves usually more than 15, sometimes up to go in number, often up to 30 cm. tall . .Isoetes melanopoda Isoetes butleri Engelm. (1: 11 ). This rare species was first discovered in Illinois in March, 1953, at Giant City State Park (Jackson County), Voigt 1320. It has since been collected in Pope County (Belle Smith Springs) and at Dixon Springs by the authors. Unlike other species of Isoetes of northeastern North America, this species grows in moist depressions on ledges of bluffs. The leaves appear in early March, the spores in mid-May, and the plants die down completely by early June. Our plants, which seldom have more than fifteen erect, slender leaves, are difficult to detect, since they grow mixed with Allium cernuum, Nothoscordum bivalve, and various grasses and sedges. Pfeiffer (1922) gives the habitat for Isoetes butleri as "limestone ledges" or "limestone barrens," but the stations in Southern Illinois are on sandstone. Our specimens have been identi- 4. EQUISETACEAE-HORSETAIL FAMILY 43 Red by Dr. Rolla M. Tryon. A previous report of this species from Illinois by Hill (1912) is an error (see Jones, 1947). SP. CIT. Giant City State Park, April 30, 1953, V 1320; April 30, 1954, M 1904. 1soetes melanopoda Gay and Durieu (1: II ). This species is larger than the preceding in all respects. Some specimens have corms which measure nearly one inch in diameter. This species is the most recent addition of a pteridophyte to Southern Illinois. It was found growing abundantly in frequently inundated roadside ditches along Illinois highway 3 between the junction with Illinois highway 144 and Fountain Bluff. It is associated at these stations with Eleocharis smallii, Callitriche heterophylla, and other amphibious species. Specimens with pale leaf-bases which occur with the species have been segregated as forma pallida (Engelm.) Fern. The nearest station of 1soetes melanopoda to the Jackson County one is in St. Clair County, about one hundred miles to the north (Neill, 1950). SP. CIT.: typical : along Illinois highway 3, two miles south of junction of Illinois highways 3 and 144, June 13, 1955, M 5386. 4. Equisetaceae - Horsetail Family Equisetum L. Equisetum arvense L. (1: 15). Common Horsetail, our most abundant Equisetum, is found along almost every railroad embankment, where it is often classed as a weed. This is a perennial species with rough, branched stems and with teeth...