• Plate I

   

  Figs. 36-42. P. americanum C. H. Ford & Stotl.-Crand. 36. Female plant with pseudoperianth (p); scale bar = 1.7 mm. 37. Male plant with antheridia (an) along the midrib and at the base of the lamellae; scale bar = 1.5 mm. 38. SEM micrograph of a female plant with young pseudoperianth; scale bar = 1.5 mm. 39. SEM micrograph of a male plant; scale bar = 1.5 mm. 40. Thallus wing showing a distinct margin (mg) of cells that are tangentially elongated (te) to slightly vertically elongate (ve); scale bar = 100 μm. 41. Lamellae showing a distinct margin of tangentially elongated cells; scale bar = 100 μm. 42. SEM micrograph of a lamella; scale bar = 100 μm.

  Figs. 36, 39-42 from Marsh and Golden 9387 (ABSH, HEND); Fig. 37 from Guerke 382 (US). Fig. 38 from Marsh and Golden 9388 (ABSH, HEND).

   

• Plate II

   

  Figs. 43-50. P. americanum C. H. Ford & Stotl.-Crandall. 43. SEM micrograph showing the ventral surface of a male gametophyte with two rows of ventral scales (v) at the apical region; scale bar = 100 μm. 44. SEM micrograph of the dorsal surface of male gametophyte showing the ( two rows of antheridia (an) that are surrounded by scale-like lamellar extensions (sl) with entire margins, formed from extensions of the dorsal lamellae; scale bar = 120 μm. 45. SEM micrograph of the dorsal surface of a female gametophyte showing an immature pseudoperianth (p) surrounding a cluster of archegonia (a); scale bar = 100 μm. 46. Plant with a mature sporophyte, with an elongated seta (se) and mature capsule (cp), and a small pseudoperianth (p); scale bar = 100 μm. 47. Architecture of the pseudoperianth mouth; scale bar = 100 μm. 48. Optical micrograph of a mass of spores (sp) and elaters (el); scale bar = 50 μm. 49. Elaters; note the 4-6 spiral thickening bands; scale bar = 20 μm. 50. SEM micrograph of a mass of spores (sp) and elaters (el); scale bar = 50 μm.

  Fig. 43 from Marsh s.n.; Figs. 44-49 from Marsh and Golden 9387 (ABSH, HEND); Fig. 50 from Marsh and Golden 9388(ABSH, HEND).

   

• Plate III

   

  Figs. 51-55. P. americanum C. H. Ford & Stotl.-Crand. 51. SEM micrograph of the distal face of a spore showing the lamellae (le) and areolae (ae); scale bar = 10μm. 52. SEM micrograph a spore in side view showing its nearly spherical shape; scale bar = 10μm. 53. SEM micrograph of a close up of the distal surface of the spore showing the lamellae (le) and areolae (ae); scale bar = 10μm. 54. SEM micrograph of a spore showing the proximal surface with the characteristic central pucker (pp); scale bar = 10μm. 55. SEM micrograph of a close up of the proximal central pucker (pp) being formed from the surrounding lamellae; scale bar = 100 μm.

  Fig. 51-55 from Krayzer JK47 (ABSH, HEND).