Xyris
Encyclopedia
Xyris is the botanical name
of a genus
of flowering plants in the Yellow-eyed-grass family. The genus counts over two hundred fifty species, with the center of distribution in the Guianas.
The leaves
are mostly distichous, linear, flat and thin or round with a conspicuous sheath at the base. They are arranged in a basal aggregation. The small, yellow flower
s are dioecious
, borne on a spherical or cylindrical spike or head (inflorescence
). Each flower grows from the axil of a leathery bract
. The fruit
is a non-fleshy, dehiscent capsule. In Xyris complanata a single flower bud on the spike appears in the morning, and expands into a conspicuous flower during the afternoon hours.
The APG II system
, of 2003, places the genus in family Xyridaceae
, in to the order Poales
in the clade commelinids
, in the monocots.
Species include:
Botanical name
A botanical name is a formal scientific name conforming to the International Code of Botanical Nomenclature and, if it concerns a plant cultigen, the additional cultivar and/or Group epithets must conform to the International Code of Nomenclature for Cultivated Plants...
of a genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of flowering plants in the Yellow-eyed-grass family. The genus counts over two hundred fifty species, with the center of distribution in the Guianas.
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are mostly distichous, linear, flat and thin or round with a conspicuous sheath at the base. They are arranged in a basal aggregation. The small, yellow flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s are dioecious
Dioecious
Dioecy is the property of a group of biological organisms that have males and females, but not members that have organs of both sexes at the same time. I.e., those whose individual members can usually produce only one type of gamete; each individual organism is thus distinctly female or male...
, borne on a spherical or cylindrical spike or head (inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
). Each flower grows from the axil of a leathery bract
Bract
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture...
. The fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
is a non-fleshy, dehiscent capsule. In Xyris complanata a single flower bud on the spike appears in the morning, and expands into a conspicuous flower during the afternoon hours.
The APG II system
APG II system
The APG II system of plant classification is the second, now obsolete, version of a modern, mostly molecular-based, system of plant taxonomy that was published in April 2003 by the Angiosperm Phylogeny Group. It was a revision of the first APG system, published in 1998, and was superseded in 2009...
, of 2003, places the genus in family Xyridaceae
Xyridaceae
Xyridaceae is the botanical name of a family of flowering plants. Such a family has been recognized by many taxonomists and is known as the Yellow-eyed-grass Family....
, in to the order Poales
Poales
Poales is a large order of flowering plants in the monocotyledons, and includes families of plants such as the grasses, bromeliads, and sedges. Sixteen plant families are currently recognized by botanists to be part of Poales....
in the clade commelinids
Commelinids
In plant taxonomy, commelinids is a name used by the APG III system for a clade within the monocots, which in its turn is a clade within the angiosperms. The commelinids are the only clade that the APG has informally named within the monocots...
, in the monocots.
Species include:
- Xyris andinaXyris andinaXyris andina is a species of plant in the Xyridaceae family. It is endemic to Ecuador. Its natural habitat is subtropical or tropical moist montanes.-Source:* León-Yánez, S. & Pitman, N. 2004. . Downloaded on 24 August 2007....
Malme - Xyris ambigua Beyrich ex Kunth
- Xyris baldwiniana Schultes
- Xyris brevifolia Michaux
- Xyris caroliniana Walter
- Xyris complanataXyris complanataXyris complanata, known as the Feathered Yellow-eye is a tufted herb in the Xyridaceae family. In New South Wales it grows in moist areas, often near swamps or in heathland.The specific epithet complanata refers to the flattened leaf stalk...
R.Br. - Xyris difformis Chapman
- Xyris drummondii Malme
- Xyris elliottii Chapman
- Xyris elongata Rudge
- Xyris exilis Doust & B.J.Conn
- Xyris fimbriata Elliott
- Xyris flabelliformis Chapman
- Xyris flexifolia R.Br.
- Xyris gracilis R.Br.
- Xyris gracillima F.Muell.
- Xyris inaequalis N.A.Wakef.
- Xyris indica L.
- Xyris indivisa N.A.Wakef.
- Xyris isoetifolia Kral,
- Xyris jupicai Richard
- Xyris juncea R.Br.
- Xyris lacera R.Br.
- Xyris lanata R.Br.
- Xyris laxiflora F.Muell.
- Xyris laxifolia Martius
- Xyris longisepala Kral
- Xyris marginata Rendle
- Xyris montana Ries
- Xyris muelleri Malme
- Xyris operculata Labill.
- Xyris pauciflora Willd.
- Xyris platylepis Chapman
- Xyris roycei N.A.Wakef.
- Xyris scabrifolia R. M. Harper,
- Xyris serotina Chapman
- Xyris smalliana Nash
- Xyris stricta Chapman,
- Xyris tennesseensisXyris tennesseensisXyris tennesseensis is a rare species of flowering plant in the family Xyridaceae known by the common name Tennessee yellow-eyed grass. It is native to a small section of the Southeastern United States, where it is known from the states of Alabama, Georgia, and Tennessee. It is threatened by the...
Kral - Xyris torta Smith
- Xyris ustulata L.A.Nilsson