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Scirpus or

Scirpus or

Scirpus

Scirpus microcarpus is a species of flowering plant in the sedge family known by the common names panicled bulrush, smallfruit bulrush, and barberpole bulrush. It is native to North America, where it can be found throughout the northern and western regions, from Alaska across Canada to the northeastern United States, in most of the central and western states, and in Baja California. It grows in many types of moist and wet habitat. It is a perennial herb growing from a long rhizome system. The erect, three-angled stems often exceed one meter tall. Sheathing leaves occur at the stem bases as well as higher up the stems. The inflorescence is a panicle of many clusters of spikelets and leaflike bracts on long, thin branches. The fruit is a pale, smooth achene less than 2 millimeters long.

Scirpus

via GIPHY

Scirpus hybrids are usually sterile, or at least show greatly reduced fertility. Interspecific hybrids are usually easy to recognize because most or all of their ovaries are empty. In addition, their spikelets are often more elongate than the spikelets of the parent species; this is probably a result of low seed sets, because growth of the spikelet is not halted as nutrition is diverted to developing seeds.Scirpus atrovirens is a common species of shores, marshes, swales, ditches and other open wet places throughout much of the state. It closely resembles 4 other Minnesota Scirpus species: Scirpus georgianus, Scirpus hattorianus, Scirpus microcarpus, and Scirpus pallidus. These share the common traits of a weakly 3-sided stem, 3 or more stem leaves, 3 or more leaf-like bracts that are shorter than to longer than the cluster branches, and a terminal cluster with fairly stiff erect to spreading branches that end in dense, hemispheric to round heads of several to many spikelets.

Scirpus atrovirens is the most common of the 4 and is distinguished by the consistently numerous and conspicuous cross-partitions on all sheaths (most evident on lower sheaths, even when sheaths/leaves dry up), floral scales usually dark brown at maturity with an awn not more than than .4mm long, 3-parted styles, 5 or 6 bristles more or less as long as the achene, and bulblets that sprout late in the season (usually present on some plants within a population, though may be absent). Cyperaceae Juss. is a cosmopolitan family, with 106 genera and approximately 5400 species (Dai et al. 2010; Spalink et al. 2016). The family is in a range from sea level up to 5475 m, covering large areas of swamp and arctic vegetation (Goetghebeur 1998). The family may have originated in the Late Cretaceous South America, and may have spread in the southern hemisphere via Antarctica (Spalink et al. 2016). Many fossils of Cyperaceae are mainly fruits or pollen. The biogeography of some genera of the family has been discussed based on fossil data, e.g. Cladium (Liang et al. 2017). Here, we report on the fruit fossils of Scirpus Linnaeus. (Source:journalofpalaeogeography.springeropen.com)

 

 

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