Microsteris

Abstract: In a recent article, Mason 1 has presented evidence on the status of Greene's genus Microsteris, and concluded that this should be lumped with Phlox L., as had been done by Greene when he first investigated the group. The writer does not concur in tha t conclusion, and presents herewith some fu r the r remarks on the subject. Grateful acknowledgment is due to the American Philosophical Society for a research grant from the Penrose Fund which has been used in support of par t of the work herein described. A word as to Kuntze 's 2 proposal of the combination Polemonium morenonis for Microsteris gracilis is first in order. Mason held that \"his reasons are forever hidden in parenthetical s y n o n y m y \" ; but his t reatment of other members of the Polemoniaceae seems to me to clarify his action. Having found that connecting links exist between practically all of the genera which had been proposed in this family, he had decided to reduce it to a single genus! On the basis of absolute priority, which he followed in choosing names, its proper name would be Polemonium, so he planned to t ransfer all members of the family to this. When he came to \"Collomia gracilis,'\" however, he found that there was already in the l i terature a Polemonium gracile, so duly coined a new specific epithet. For tunately he did not live long enough to carry this project beyond a few South American species. The assignment of the enti ty in question by Douglas and by Bentham to the genus CoUomia was after all not unreasonable, for it shows the following coUomiold characters: persistent cotyledons, accrescent calyx, subequal sepals, basally flaring corolla-tube, inner surface of corolla-tube just above base glabrous or at most sparsely pubescent, and brown translucent-coated seeds becoming viscid when wet. They merely failed to realize the diagnostic significance of calyxmembrane characters, which are here not at all collomioid. Many of the features listed are also shown by gilioid members of the family, and Hooker actually made the plant a Gilia, but not one of them is typically phlogoid. Relationship to Phlox is shown, however, in the opposite position of leaves at several nodes, in the scarious junction-membranes of the sepals, in the firm concave capsule-valves, and in the chromosome number of 7. An enti ty combining the characters of several genera to such an extent surely does not belong to any of them, bu t deserves segregation as an independent genus. In the article cited, Mason noted that only two characters had been put forward to separate Microsteris f rom Phlox, and that these are scarcely of generic significance. That there are also others, however, is brought out in the following table. The list of contrasted characters is actually larger than can be drawn up for distinguishing most other pairs of genera in the family Polemoniaceae. The writer accordingly desires to reaffirm his view that Microsteris merits independent generic status.