Learning about flowering plants (angiosperms) can be a lifelong study for a gardener. One report states that they include 416 families, approximately 13,164 known genera and about 295,383 known species. Angiosperms are within the group called vascular land plants, i.e., plants that have specialized tissues for conducting water and minerals throughout the plant, and for conducting the products of photosynthesis.
Other kinds of vascular land plants include clubmosses, horsetails, ferns, and gymnosperms (e.g., conifers). Seaweeds and other plants that grow in water (aquatics) are in a different group.
The scientific term for vascular land plants is Tracheophytes, a name with the same root as our own windpipes (trachea). The suffix “–phytes” means “plants.”
The complement to vascular land plants could be non–vascular land plants, which do not have the specialized tissues of vascular plants, and that have very different ways to grow and propagate. For example, instead of roots they have rhizoids, which are similar to the root hairs of vascular plants.
Non-vascular land plants, called Bryophytes (“moss plants”), have three divisions: mosses, liverworts and hornworts. There are some 18,400 species among the Bryophytes, including about 13,000 mosses, 5,200 liverworts and just 200 hornworts. This group is clearly much smaller in number than the Tracheophytes. The plants also are typically much smaller in size, even in some cases microscopic.
The current issue of Fremontia, the journal of the California Native Plant Society, includes an absorbing article on Bryophytes, and suggests that we should care about them because of their aesthetic charm, contributions to biodiversity, and ecological functions, which include hydrological buffering and nutrient cycling.
Because of such qualities, about two years ago interested persons formed the Bryophyte Chapter of the California Plant Society, to “increase understanding and appreciation of California’s mosses, liverworts, and hornworts—and to protect them where they grow.” For information on this CNPS chapter, visit its website.
The aesthetic aspect of Bryophytes, particularly for mosses, might be interesting to gardeners and landscapers. Moss gardening can be a fascinating pursuit for the adventurous gardener with sufficient time and patience.
There are moss varieties for many different situations, including both sunny and shady settings as well as a wide range of soil types (except sand). Growing mosses for an unusual garden bed or between stepping stones or pavers can take a year or two and consistent irrigation. For information on such projects, search the Internet for “moss gardens” or visit the website of Moss & Stone Gardens.com for the useful paper, “How to Grow Moss.”
Bryophytes and especially mosses are an under-appreciated and fascinating part of the plant kingdom, and mosses could be a welcome addition to the home garden.