genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of
flowering plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...
s of the grass family,
Poaceae
Poaceae ( ), also called Gramineae ( ), is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos, the grasses of natural grassland and species cultivate ...
. They are known commonly as rosette grasses and panicgrasses.''Dichanthelium''. USDA PLANTS.
Taxonomy
Formerly a subgenus of the genus '' Panicum'', ''Dichanthelium'' was elevated to genus status in 1974. Its species are still treated as members of ''Panicum'' by some authorities, because the two genera are very similar in form. Molecular data support the recognition of ''Dichanthelium'' as a separate genus.Freckmann, R. W. and M. G. Lelong ''Dichanthelium''. The Grass Manual. Flora of North America.
The name ''Dichanthelium'' originates from the Greek for "twice-flowering", in reference to the vernal and autumnal growth phases.
Description
These are perennial grasses, sometimes with
rhizome
In botany and dendrology, a rhizome ( ) is a modified subterranean plant stem that sends out roots and Shoot (botany), shoots from its Node (botany), nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from ...
s. The grasses may overwinter as rosettes of short, wide leaves and then produce longer, wider leaves on the stem during spring. They produce hollow stems a few centimeters tall to well over one meter. They are upright to erect when new, then sometimes sprawling, spreading, and bending as the season progresses. The upper stems may have a few main branches that divide into smaller branches bearing
panicle
In botany, a panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit) be pedicellate (having a single stem per flower). The branches of a p ...
s. There are primary panicles, which may be chasmogamous, and secondary panicles, which are often cleistogamous. The spikelets are roughly 1 to 5 millimeters long and lack awns.
In the Chicago area, ''Dichanthelium'' is considered the most emblematic genus of the
Gulf
A gulf is a large inlet from an ocean or their seas into a landmass, larger and typically (though not always) with a narrower opening than a bay (geography), bay. The term was used traditionally for large, highly indented navigable bodies of s ...
and
Atlantic coastal plain
The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...
Dichanthelium scoparium
''Dichanthelium scoparium'' is a species of Poaceae, grass known by the common names velvet panicum, velvety panicgrass, and broom panicgrass. It is native to North America, where it occurs in the southeastern United States. It also occurs in the ...