Status: Native
Synonyms:
Mnium pseudopunctatum Bruch & Schimper
Rhizomnium pseudopunctatum does not have the long, green-stemmed horizontal branches that
characterize the genus Plagiomnium. It does have cells that are called "micronemata". These
can be recognized as cells in the stem that are broader and shorter, more rectangular than the linear
narrow cells that make up most of the stem visible from the exterior. They seem to give rise to rhizoids
all the way up the stem to the youngest leaves rather than being confined to the bottom of the stem. Even
if the rhizoids aren't present, the micronemata are visible on the stem. The leaves
of Rhizomnium pseudopunctatum are obovate to orbicular and have cells that are generally 30-80μm in length
rather than the longer cells of other species in the genus. The margin is unistratose. Terry T. McIntosh makes the
distinction (in FNA vol. 28) that the mildly pitted laminar cells of Rhizomnium pseudopunctatum are
nevertheless more pitted than those of R. magnifolium, which usually also has larger leaves. R. magnifolium also usually has a 2-stratose margin. Mahler found this specimen of Rhizomnium pseudopunctatum at upper elevation (9,900 feet) in Colfax County.
We appreciate the Botanical Research Institute of Texas and Tiana Rehman for loaning us William F. Mahler's
Mnium pseudopunctatum specimen to photograph!
Please click on an image for a larger file.
Rhizomnium pseudopunctatum, specimen collected by Wm. F. Mahler, Colfax Cty, Forest Road 76 near junction with Osha Pass road, in spruce-aspen forest on bank above stream, July 1, 1979, photo Russ Kleinman & Karen Blisard, May 8, 2022
Rhizomnium pseudopunctatum, light field photomicrograph of stem, specimen collected by Wm. F. Mahler, Colfax Cty, Forest Road 76 near junction with Osha Pass road, in spruce-aspen forest on bank above stream, July 1, 1979, photo Russ Kleinman & Karen Blisard, May 8, 2022
Rhizomnium pseudopunctatum, dark field photomicrograph of stem, specimen collected by Wm. F. Mahler, Colfax Cty, Forest Road 76 near junction with Osha Pass road, in spruce-aspen forest on bank above stream, July 1, 1979, photo Russ Kleinman & Karen Blisard, May 8, 2022
Rhizomnium pseudopunctatum, dark field photomicrograph of leaf, specimen collected by Wm. F. Mahler, Colfax Cty, Forest Road 76 near junction with Osha Pass road, in spruce-aspen forest on bank above stream, July 1, 1979, photo Russ Kleinman & Karen Blisard, May 8, 2022
Rhizomnium pseudopunctatum, photomicrograph of stem micronemata, specimen collected by Wm. F. Mahler, Colfax Cty, Forest Road 76 near junction with Osha Pass road, in spruce-aspen forest on bank above stream, July 1, 1979, photo Russ Kleinman & Karen Blisard, May 8, 2022
Rhizomnium pseudopunctatum, photomicrograph of leaf apex, specimen collected by Wm. F. Mahler, Colfax Cty, Forest Road 76 near junction with Osha Pass road, in spruce-aspen forest on bank above stream, July 1, 1979, photo Russ Kleinman & Karen Blisard, May 8, 2022
Rhizomnium pseudopunctatum, photomicrograph of leaf margin and small laminal cell size, specimen collected by Wm. F. Mahler, Colfax Cty, Forest Road 76 near junction with Osha Pass road, in spruce-aspen forest on bank above stream, July 1, 1979, photo Russ Kleinman & Karen Blisard, May 8, 2022
Rhizomnium pseudopunctatum, photomicrograph of pitted lamina cells, specimen collected by Wm. F. Mahler, Colfax Cty, Forest Road 76 near junction with Osha Pass road, in spruce-aspen forest on bank above stream, July 1, 1979, photo Russ Kleinman & Karen Blisard, May 8, 2022
Rhizomnium pseudopunctatum, photomicrograph of leaf cross section, specimen collected by Wm. F. Mahler, Colfax Cty, Forest Road 76 near junction with Osha Pass road, in spruce-aspen forest on bank above stream, July 1, 1979, photo Russ Kleinman & Karen Blisard, May 8, 2022
Rhizomnium pseudopunctatum, photomicrograph of unistratose leaf margin, specimen collected by Wm. F. Mahler, Colfax Cty, Forest Road 76 near junction with Osha Pass road, in spruce-aspen forest on bank above stream, July 1, 1979, photo Russ Kleinman & Karen Blisard, May 8, 2022
Rhizomnium pseudopunctatum, 600x photomicrograph of unistratose leaf margin, specimen collected by Wm. F. Mahler, Colfax Cty, Forest Road 76 near junction with Osha Pass road, in spruce-aspen forest on bank above stream, July 1, 1979, photo Russ Kleinman & Karen Blisard, May 8, 2022
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