Nebraskaland

while he was a botany student at the University of Washington. During his long career at UNO, however, his expertise was in grasses, and in 2007 he coauthored The Flora of Nebraska (vascular plants). Ten years ago, when Sutherland retired, spare time allowed him to rekindle his interest in non-vascular plants. Over the last decade, Sutherland along with Rob Harms, a former UNO graduate student in biology, have taken numerous weekend excursions throughout the state collecting bryophytes. Of late, Nebraska botanists Bob Kaul, recently retired from the University of Nebraska-Lincoln, and Steve Rolfsmeier of Chadron State College, have also taken a keen interest in bryophytes. The foursome's goal is to document which bryophyte species grow in Nebraska, their distribution, habitats and abundance and to eventually publish a flora of Nebraska's non-vascular plants with a species key, range maps and some illustrations. To date, they have verified about 220 bryophyte species for Nebraska. The majority are mosses. Few botanists had previously studied Nebraska's non-vascular flora. In the 1940s, Walter Kiener, a Swiss-born biologist with the Nebraska State Game, Forestation, and Parks Commission, undertook the first extensive surveys for Nebraska bryophytes. Over his career, Kiener was a prolific collector of not only bryophytes, but also vascular plants and lichens. The moss Splachnobyrum kieneri was named in his honor. In the late 1970s and early 1980s, then UNL botany student Steve Churchill collected bryophytes in the central Niobrara River valley in Brown, Keya Paha and Cherry counties and elsewhere in the state and first catalogued our state's non-vascular flora. Churchill went on to become a renowned bryologist and is presently working in the rainforests of Bolivia. The central Niobrara valley, with its many cool, spring-fed side canyons, is also among Sutherland's and Harms's favorite collecting sites. In the steep canyons, below a sheltering canopy of paper birch and basswood, continually damp streamside rocks and tree trunks are cloaked in mossy greenness. Over 40 species of uncommon northern mosses and liverworts grow in the valley's unique microclimate. Most are likely Ice Age relicts, stranded here about 12,000 years ago as the post-glacial climate warmed and the glaciers retreated northward. Closer to their homes in Omaha, Sutherland and Harms also frequent Schramm Park State Recreation Area on the Platte River bluffs in Sarpy County, as its oak woods and calcareous rock outcrops are prime moss habitat. Here, they recently discovered Hedwig's fringleaf The Ancient Bryophytes One of the bryophytes' primitive characteristics is their lack of vascular tissues for transporting water, sugar and nutrients. By comparison, the more modern vascular plants, such as ferns and flowering plants, have phloem and xylem as transport tissues, which allow for larger and upright growth. Bryophytes also lack true roots, and instead have short, root-like anchoring structures called rhizoids that aid in attachment to rocks, trees and other surfaces. Lacking roots, bryophytes must absorb water and nutrients through their leaves or thalli (defined below), explaining their preference for moist environments. Another ancient characteristic: mosses, hornworts and liverworts reproduce by spores rather than seeds and lack flowers. Mosses, similar to vascular plants, have stems and leaves, though the former are short and the latter but one-cell thick. Able to reproduce vegetatively, most mosses grow in clumps or mats of compacted individual plants. During the warmth of summer, delicate, long-stalked spore capsules rise above the leaves. Each capsule can contain millions of microscopic spores that, when released, become waifs in the wind traveling great distances. Hornworts are strange plants in that they lack stems and leaves, and have a main body consisting of a green, flat structure called a thallus. Unique among plants, they have but a single large, algal-like chloroplast in each thallus cell which is responsible for photosynthesis. Arising from the thalli are their namesake, horn- shaped spore capsules. Liverworts come in two forms. Some, similar to hornworts, are thalloid, but most are leafy and appear as flattened moss. The leafy forms are distinguished from mosses by not having well differentiated stems and leaves, and the latter lack the thickened central midrib of moss leaves. Liverwort spore capsules are of various forms. In the genus Riccia, for example, the capsules are imbedded in the thalli: in other genera, they are stalked. The name "liverwort" is derived from the liver shape of some thalloid types. ■ 38 NEBRASKAland • MARCH 2017

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