Notes on Infrequent and Threatened Plants of Maryland Including New State Records

ABSTRACT
As a consequence of active interest in the endangered species of Maryland and the northeastern United States in general, a critical appraisal and evaluation of the rare plants of the state was undertaken. This field and herbarium study has uncovered seven previously unreported indigenous taxa in the state, namely: <em>Carex exilis</em>, <em>Cymophyllus fraseri</em>, <em>Arenaria stricta</em>, <em>Ceratophyllum echinatum</em>, <em>Potentilla tridentata</em>, <em>Viola rostrata</em>, and <em>Cornus rugosa</em>. In addition, 47 new inclusions are suggested for monitoring on the Maryland list of endangered and threatened plants and 27 changes in status from the previously published list are indicated due to the increased locality data available. Herbarium vouchers are cited wherever necessary.