Rare Iowa Plant Notes from the R. V. Drexler Herbarium

Notes on the distribution, habitats, associated species, and taxonomic considerations for 134 rare Iowa plants are presented. These taxa, including 15 Pteridophytes, 74 Dicots, and 45 Monocots were located during a decade of field research (1979-1989) concentrated in eastern, northeastern, and northwestern Iowa. Included among these are 10 taxa previously unrecorded from the Iowa flora (Carex sterilis, Circaea X intermedia, Cypripedium calceolus var. parviflorum, Lycopodium inundatum, Opuntia macrorhiza, Salix candida X Salix rigida, Salix X clarkei, Solidago uliginosa, Spiranthes ova/is, Viola adunca), and 15 taxa (Angelica atropurpurea, Aristolochia serpentaria, Artemesia frigida, Aster linariifolius, Berula pusilla, Carex conoidea, Eleocharis pauciflora var. fernaldii, Erythronium americanum, Galium labradoricum, Hypericum gentainoides, Juncus marginatus, Potentilla pensylvanica, Salix candida, Viola renifolia, and Xyris torta) which were once feared extirpated from the state (based on Roosa and Eilers 1978, Howe et al. 1984). The remainder of the species discussed are rare in Iowa or are restricted to special habitats within the state, including algific talus slopes, fens, and vernal pools