Juncus conglomeratus
Common names
soft rush
Biostatus
Exotic
Category
Vascular
Structural class
Rushes & Allied Plants
Simplified description
Upright clump-forming leafless rush to 80 cm tall, with tall cylindrical stems, with tightly clustered spherical flowerheads near the end of each stem, made up of many red-brown flowers/capsules (fruit).
Flower colours
Brown
Detailed description
Erect clumps; rhizomes short. Stems 30–80 cm × 1.5–3 mm, soft and easily split, grey-green, dull, prominently ridged especially just below inflorescence, pith continuous, cobwebby. Basal sheaths brownish-red, not shining. Inflorescence a ± spherical head c. 1 cm long, base of subtending floral bract conspicuously red-tinged and expanded to a wide opening through which inflorescence emerges. Flowers very crowded. Tepals 2–2.5 mm long, ± equal, acuminate. Stamens 3. Capsule c. 2 mm long, ± = tepals, ovoid-oblong, flattened at top, reddish-brown.
Similar taxa
Similar to other tall leafless rushes, but has a dense single flower cluster, with an expanded floral bract behind it and conspicuous ridges on the stem beneath the inflorescence.
Distribution
Tasman to Southland.
Habitat
Lake margins, roadside drains and wet pasture.
Conservation status
Not applicable
Detailed taxonomy
Family
Synonyms
Agathryon conglomeratum (L.) Záveská Drábková & Proćków
Taxonomic notes
Subgenus Agathyron, Section Juncotypus (Genuini) Kirschner (2002: Juncaceae 3)
Proćków et al. (2023) proposed a taxonomic segregation of Juncus into six genera based on molecular and morphological evidence. Whilst it has long been recognised that the current circumscription of Juncus includes morphologically divergent taxa—reflected in the recognition of numerous subgenera and sections—the consensus view of the NZPCN website taxonomy subcommittee, taking into consideration advice from Australian Juncus expert Dr Karen Wilson (NSW Herbarium) and others in Europe is that the generic segregations proposed need further consideration and testing. Accordingly, it has been decided to maintain the current broad circumscription of Juncus, but to include all new names as synonyms in factsheets. We thank, in particular, Dr Wilson for her helpful comments.
Ecology
Flowering
Spring to early summer
Fruiting
Summer to autumn
Year naturalised
1930
Origin
Europe, Western Asia Northwestern Africa and North America
Reason for introduction
Unknown, seed or soil contaminant.
Control techniques
Not controlled in New Zealand.
Life cycle and dispersal
Seed dispersed by animals, water or contaminated machinery.
Wetland plant indicator status rating
Information derived from the revised national wetland plant list prepared to assist councils in delineating and monitoring wetlands (Clarkson et al., 2021 Manaaki Whenua – Landcare Research Contract Report LC3975 for Hawke’s Bay Regional Council). The national plant list categorises plants by the extent to which they are found in wetlands and not ‘drylands’. The indicator status ratings are OBL (obligate wetland), FACW (facultative wetland), FAC (facultative), FACU (facultative upland), and UPL (obligate upland). If you have suggestions for the Wetland Indicator Status Rating, please contact: [Enable JavaScript to view protected content]
FACW: Facultative Wetland
Usually is a hydrophyte but occasionally found in uplands (non-wetlands).
Other information
Etymology
juncus: From the Latin jungere ‘to tie or bind’, the stems of some species being used to make cord (Johnson and Smith)
NVS code
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
JUNCON
Referencing and citations
References and further reading
Champion et al. 2012. Freshwater Pests of New Zealand. NIWA publication. http://www.niwa.co.nz/freshwater-and-estuaries/management-tools/identification-guides-and-fact-sheets/freshwater-pest-species
Healy, A. J. 1982. Identification of weeds and clovers. New Zealand Weed and Pest Control Society Publication. Editorial Services Limited, Featherston. 299 p.
Healy, A. J.; Edgar, E. 1980. Flora of New Zealand, Volume III. Adventive Cyperaceous, Petalous and Spathaceous Monocotyledons. Government Printer, Wellington. 220 p.
Johnson P. N., Brooke P. A. 1989. Wetland plants in New Zealand. DSIR Field Guide, DSIR Publishing, Wellington. 319pp.
Johnson, A. T. and Smith, H. A. 1986. Plant Names Simplified: Their pronunciation, derivation and meaning. Landsman Bookshop Ltd, Buckenhill, UK.
Kirschner, J. (compiler) 2002. Juncaceae 3: Juncus subg. Agathryon, Species Plantarum: Flora of the World Part 8: 1–192.
Proćków, J., Záveská Drábková, L. 2023. A revision of the Juncaceae with delimitation of six new genera: nomenclatural changes in Juncus. Phytotaxa 622(1): 17–41.
Attribution
Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA). Feature description from healy and Edgar (1980).
Some of this factsheet information is derived from Flora of New Zealand Online and is used under a Creative Commons Attribution 3.0 New Zealand licence.