Juncus dichotomus

Juncus dichotomus
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Monocots
Clade:	Commelinids
Order:	Poales
Family:	Juncaceae
Genus:	Juncus
Species:	J. dichotomus
Binomial name
Juncus dichotomus Elliott[1]
Synonyms[2]
Juncus albicans Fernald Juncus cognatus Kunth Juncus platyphyllus (Wiegand) Fernald

Juncus dichotomus (common name is forked rush^[3]) is a monocot which belongs to the Juncaceae family of rushes. The plant is native in the Americas in temperate zones but has been introduced to other parts of the world. The species is often confused with other Juncus plants due to morphological similarity. Juncus dichotomus often is found in areas which prove to be very moist, and rainfall is a common occurrence. Juncus dichotomus is often most recognizable in the spring and summer months of the year due to its conspicuous flowers and infructescence.

This plant can be difficult to identify due in part to its similar appearance to other Juncus species.^[4] Often Juncus dichotomus is overlooked because it is inconspicuous in the field, and some can be difficult to identify and some consider Juncus dichotomus a weed.

Description[]

Juncus dichotomus is a graminoid, i.e., a grass-like plant.^[5] Juncus dichotomus belongs to the monocot group in which it is a member of a Juncaceae family otherwise known as the rushes.^[5] While this species of rush is not tall and lacks many distinctive features making it especially hard to identify by non-specialists. In North America July through August is when Juncus dichotomus is most frequently observed. Juncus dichotomus can occur in dry sites but it thrives best in soils that are damp, such as a roadside ditches where runoff is frequent.^[4][6]

Habitat/distribution[]

Juncus dichotomus is native and distributed widely in the Americas in temperate zones but has been reported as introduced in other temperate climate zones. Juncus dichotomus is a more specialized species least temporarily wet habitats: riverbanks, pond margins, depressions in heaths, sometimes also near rice fields.^[7] Flowering and fruiting occurs in late spring—summer in ditches, shores, clearings, and other typically open areas, usually in sandy, well-drained (but frequently wet) soil.^[8] Juncus dichotomus usually grows in sandy soils.^[4] Any habitat that hold sufficient groundwater with stable temperate temperatures, then this location has the capability to hold a population of J. dichotomus.

^{[5] [8]}

Taxonomy[]

^[1] .^[4] Juncus dichotomus is considered perennial herbs to 10 dm. Rhizomes densely branched to short creeping. Cataphylls 1--3. Leaves basal; auricles 0.2--0.5(--0.6) mm, scarious to leathery; blade nearly terete, channeled or flat, 10–25(--40) cm(0.5--)0.7--1(--1.2) mm, margins entire. Inflorescences terminal, (5--)10–85(--100)-flowered, congested to somewhat loose, (1--)2.5--10–13) cm; primary bract usually exceeding inflorescence. Flowers: bracteoles 2; tepals green, lanceolate, (3--)3.3--4.5(--5.5) mm; outer and inner series nearly equal; stamens 6, filaments 0.6--1.2 mm, anthers 0.4--0.8(--1) mm; style 0.2 mm. Capsules tan to brown, 1-locular to pseudo-3-locular, ellipsoid to widely. Seeds brownish to amber, ellipsoid to lunate, 0.3--0.4 mm, not tailed. 2n = ca. 80.^[9]

Uses[]

The uses for Juncus dichotomus are limited. Since the plant is often found next to or near water sources which may play a role in preventing erosion.

Management[]

Juncus dichotomus, a native of the Americas, is also now being reported as invasive in Europe.^[4] Juncus dichotomous has been confused with Juncus tenuis, a very widespread plant, in Europe which may have contributed to its spread there.^[7] Throughout the southeastern United States and some Northeastern parts on the US found there dichotomus is common.^[5] Systemic rusts and smuts have a major effect on individual plants and populations as they affect growth and survival and diseased plants may become distorted, stunted and/or elongated although the results are variable.^[10] More work on the life history of J. dichotomus is required to better understand how it responds to disease and other abiotic factors.^[10] Management of this species as an invasive in Europe is unclear, although water regime is important and may be manipulated to control the plant as well as herbicides

History[]

It is clear that Juncus dichotomus has increased its range substantially due to human aided dispersal. Although the biogeographic history of J. dichotomus is somewhat unclear due in part to its similarities with other graminoid species.^[4]

References[]