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154 Lloyd and Underwood : A Review of the 



L. alopcatroides, var. adpressum Chapm. Fl. So. States, ed. 

 3, 638. 1897. 



Stems prostrate and frequently rooting or slightly arching and 

 rooting toward the end, 18-40 cm. long, simple or occasionally 

 pinnately branching, thick (about 3 mm. in diameter) : leaves 6-7 

 mm. long by 2 mm. broad, thicker and more rigid than in the last, 

 lanceolate-acuminate, upwardly curving, the margin irregularly 

 toothed, the teeth often compound below the middle of the leaf: 

 peduncles 10-25 cm. long usually tall, slender (1.5-2.5 mm. in 

 diameter), leafy with more or less appressed subulate -toothed leaves 

 below and similar entire leaves above : strobiles narrow, about 3 

 mm. in diameter, and 1.8-7 cm. long: sporophylls 1 mm. x 

 5-6 mm. with a broad base, suddenly contracted above into a 

 narrow subulate apex, usually more or less toothed near the base : 

 sporangia subglobose. 



Readily distinguishable from L. inundatum by the much thicker 

 stems, toothed leaves, tall peduncles and long narrow spikes. 



An abnormal condition occurs in which the strobiles fail to 

 develop and the branches rise to an unusual height (35 cm.). Lake 

 Worth, Florida, L. M. Underwood (U). One peduncle on the 

 same sheet bears a strobile of unusual size (1 1 cm.) 



In the northern part of its range, this plant is much smaller and 

 is difficult to distinguish from L. inundatum Bigelovii, from which, 

 however, it differs in its thicker stem, in the shape of its leaves, and 

 in the degree of their denticulation which, however, is constant in 

 the leaves of the prostrate stems, but the constancy frequently fails 

 in the peduncular leaves. 



Alth 



a dis- 



tinct species, and is believed to be entitled to such rank, it must 

 be admitted that from the true boreal species, L. inundatum, to the 

 large southern L. adpressum there are many forms which on ac- 

 count of variations in size of stem, denticulation and variations in 

 the size and shape of leaf and sporophyll are difficult to place. It 

 will, however, be found convenient to hold to the above arrange- 

 ment as tentative in the hope that further and more careful field 

 observations will help to clear up the whole matter. It is further 

 of great interest to note that a single species which in Europe 

 shows little variability is in America only a representative of a 

 plexus of forms ranging from that species at one end of the series 

 to the extremely curious plant, L. alopccuroidcs, at the other. 



