Three dominant life forms are immediately apparent in the Boulder Patch: (1) a large, mostly homogenous kelp population, (2) a seemingly ubiquitous crustose algal population, and (3) clumps of delicate or coarse thalloid reds and browns, often long-lasting, loose-lying populations.
The Boulder Patch algal community contains several loose-lying forms of algae that are typically recognized as attached thalloid and leafy red and brown algal species.
Rare in silt-packed crevices in west-facing limestone faces, with Cheilanthes acrostica (CJR 2753), a big thalloid
liverwort (CJR 2750), mosses, etc.
An exception to this general plan in bryophytes occurs in certain complex thalloid
liverworts, such as Conocephalum conicum (Brown & Lemmon, 1988c) where spores are not in tetrahedral arrangement and cleavage planes are determined after meiosis by interaction of opposing sets of radial microtubules emanating from the four nuclei.
The widespread and conspicuous simple thalloid
liverwort Pallavacinia was a favorite subject of the early cytologists who described quadrilobing of the sporocyte and the quadripolar origin of the spindle (e.g.
Diversity in meiotic spindle origin and determination of cytokinetic planes in sporogenesis of complex thalloid
Such a "dorsiventral bifacial" thalloid
structure is considered probable in the ancestry of land plants, according to some theories of land-plant origin (cf.