Phaeoceros carolinianus (Michaux) Proskauer
Description: Phaeoceros carolinianus is a hornwort with a smooth, deep-green thallus, which forms irregular, dichotomously branching ribbons. Here in Santa Barbara County, I have found it only at Nojoqui Falls. It is our only species that lacks both lamellae and tubers. Sporophytes are 2-5 cm tall, and mature spores are yellow, with fine spines on the distal face. In the absence of spores, it is helpful to look for antheridial pits on the upper surface, each containing 2-4 antheridia (male structures containing sperm), which are pale and quite large (up to 150 μm). Thallus cells have one large chloroplast with a central pyrenoid, visible as bumps or ridges at high magnification. Large, black, spherical colonies of cyanobacteria are often visible, particularly on the underside of the thallus.
Key Characters:
- Thallus: variable shape, solid (no cavities), smooth (no lamellae)
- Tubers: none
- Sporophytes: 2-5 cm tall
- Spores: yellow, fine spines on distal face, fewer than 30 warts on proximal face
- Pseudoelaters: 3-4 cells (but may disintegrate)
- Chloroplasts: usually 1/cell, with central pyrenoid visible as a bump or ridges
Scroll down for photos illustrating habitat, form, antheridial pits, Nostoc colonies, chloroplasts and spores (click to enlarge).
Bryophytes of Santa Barbara 