02063nas a2200205 4500008004100000245014000041210006900181300001200250490000700262520134800269653003701617653001401654653004101668653003101709653001901740653002001759100001901779700002101798856003801819 2010 eng d00aIntroduction and recent range expansion in the moss Ptychomitrium serratum (Ptychomitriaceae) in the Southern and Eastern United States0 aIntroduction and recent range expansion in the moss Ptychomitriu a336-3440 v883 a

The moss Ptychomitrium serratum (C. Müll. Hal. ex Schimp.) Besch., is native to Mexico and parts of western Texas and southern New Mexico, and it is a rare adventive in the area from East Texas and Louisiana to Missouri, Tennessee, South Carolina, and northward to locations near the coast in New York State and Massachusetts. In the adventive part of this calcicole’s range, all collections are from the past 50 years. Concrete, mortar, and rarely asphalt shingle are its only known substrata in this region, which contrasts sharply with its common occurrence on limestone in the native portion of its range. These observations indicate recent, perhaps on-going, immigration into the eastern United States and dispersal from established populations in this region. This monoicous moss commonly produces spores, which are its primary means of spread. Given the low density occurrences in the adventive portion of the range of P. serratum, dispersal may be generally northeastward from Mexico – Texas – New Mexico, following northeastward storm tracks in the southern and eastern United States. The apparently recent spread of this moss does not show obvious reliance on any direct human activity.

10aadventive and naturalized mosses10acalcicole10aconcrete and mortar as moss habitat.10aplant introduction history10aspecies rarity10aspore dispersal1 aMiller, N., G.1 aRobinson, S., C. uhttp://dx.doi.org/10.1139/B09-099