Plantae Coulterianae: Thomas Coulter’s Californian Exsiccata

An account of the extent, diversity, and importance of the Californian collections of Thomas Coulter in the herbarium (TCD) of Trinity College, Dublin, Ireland, is presented here. It is based on examination of collections in TCD, several other collections available online, and referenced literature. Additional information on historical context, content of herbarium labels and annotations is included. Coulter’s collections in TCD are less well known than partial duplicate sets at other herbaria. He was the first botanist to cross the desert of southern California to the Colorado River. Coulter’s collections in TCD include not only 60 vascular plant specimens previously unidentified as type material but also among the first moss and marine algae specimens known to be collected in California. A list of taxa named for Thomas Coulter is included. Images of the map of his route are presented here as well as comments on some locality errors. Mention is made of works cited in annotations that were, in fact, never published, leading to persistent author citation errors. Coulter’s expansive interests in collecting and natural history included languages of the indigenous tribes he encountered in California