Myosotis laxa subsp. caespitosa
Common names
water forget-me-not
Biostatus
Exotic
Category
Vascular
Structural class
Herbs - Dicotyledons other than Composites
Simplified description
Low growing herb on wet ground and damp hollows. Leaves are pale green, stems often bend at the base and leaves are willow like. The flowers are small, pale blue with a yellow center.
Flower colours
Blue, Yellow
Detailed description
Plants are annual or biennial and 20 to 40 cm tall. Stems are decumbent or ascending. Leaves are narrow, alternate and attached directly to the stem and have pointed or rounded tips with a prominent mid-vein. Leaves usually 30 to 60 mm long, pale green with sparse appressed hairs. Flowers are 2 to 4mm wide, pale blue (with yellow centre). Pedicels at fruiting 2 to 3 times as long as calyx. Nutlets (4) are dark brown.
Similar taxa
M. scorpioides is similar, but has larger floweres and small calyx lobes.
Distribution
Widespread and very common throughout New Zealand.
Habitat
Margins of ponds and streams and wet hollows, growing submerged in clear fast-flowing streams.
Conservation status
Not applicable
Detailed taxonomy
Family
Synonyms
Myosotis caespitosa CF Schultz
Ecology
Flowering
September to May
Fruiting
Summer to autumn
Year naturalised
1892
Origin
Temperate Eurasia, East to Himalaya
Reason for introduction
Ornamental pond and garden plant
Control techniques
Can be controlled manually, mechanically or herbicidally depending on situation.
Life cycle and dispersal
Mainly seed dispersal by water movement and animals contaminated with hooked persistent calyx surrounding seed.
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]
OBL: Obligate Wetland
Almost always is a hydrophyte, rarely in uplands (non-wetlands).
Other information
Etymology
myosotis: Mouse-eared
laxa: Slack, loose
caespitosa: From the Latin caespes ‘tuft’ or ‘sod of turf’, meaning growing in tufts or patches
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.
MYOLSC
Referencing and citations
References and further reading
Johnson PN, Brooke PA (1989). Wetland plants in New Zealand. DSIR Field Guide, DSIR Publishing, Wellington. 319pp.
Popay et al (2010). An illustrated guide to common weeds of New Zealand, third edition. NZ Plant Protection Society Inc, 416pp.
WSDE (2001). An aquatic plant identification manual for Washington’s freshwater plants. Washington State Department of Ecology, 195pp.
Attribution
Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA).