Paraphymatoceros pearsonii (M. Howe) J.C. Villarreal & Cargill
Description: Paraphymatoceros pearsonii is a hornwort with medium-sized, usually strap-shaped thalli with somewhat wavy edges, and with thickened, disc-shaped tubers at the lobe tips and margins. Individual plants are monoicous, bearing both male and female organs, but are said to be “strongly protandrous,” such that male antheridia appear much earlier than the female archegonia, presumably reducing self-fertilization. Plants are usually found with sporophytes, which reach 2-4 cm in length, turning first yellow-ish brown, and finally dark brown at the tips, splitting open to release the spores. Mature spores are yellow to brown, with large warts on the distal surface, and a smooth proximal surface. Pseudoelaters are said to be 3-4 cells, but in my experience, this is true of only a few pseudoelaters within a sporophyte, with most seemingly broken down to 2 cells or a single cell.
Key Characters:
- Thallus: variable, usually strap-like, solid (no cavities)
- Tubers: flattened disks at lobe tips and along margins
- Sporophytes: 2-4 cm long
- Spores: yellow to brown, 8-15 warts on distal face, proximal face smooth or obscured
- Pseudoelaters: 3-4 cells (but may disintegrate)
- Chloroplasts: usually 1/cell, without pyrenoids
- Antheridia: one per pit, 100-200 µm
Scroll down for photos illustrating habitat, form, antheridia, chloroplasts, pseudoelaters and spores (click to enlarge) .
Bryophytes of Santa Barbara 