Species

Symphyotrichum subulatum

Etymology

subulatum: awl-shaped

Common Name(s)

Bushy starwort, sea aster

Authority

Symphyotrichum subulatum (Michx.) G.L. Nesom

Family

Asteraceae

Brief Description

Tall, spindly, straight-stemmed almost hairless annual or short-lived perennial herb up to 2 m tall, with small pale purple flowers produced on a many-branched flower stalk

Flora Category

Vascular - Exotic

NVS Species Code

ASTSBL

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.

Synonyms

Aster subulatus Michx.

Distribution

Common in the North Island, also established in northern South Island.

Habitat

Wetland margins and coastal places, also in drier habitats including roadsides, wasteland and open grassland.

Features

Tap-rooted annual or short-lived perennial herb, glabrous or rarely with a few hairs on upper stem; stems erect, terete, sparingly branched below, 20-200 -(300) cm tall, rarely stems resprouting and somewhat woody after flowering. Mid cauline lvs lanceolate to linear, apetiolate and cuneate, acute, crenulate or remotely serrulate, 35-150 × 3-10-(20) mm; lowermost lvs mostly petiolate, elliptic, cuneate, obtuse; uppermost lvs linear. Infl. a many-headed diffuse panicle. Capitula 2-5 mm diam. Involucral bracts very unequal; inner bracts narrow-oblong to subulate, acute to slightly acuminate, green toward apex and along midrib, purplish at apex and margins, 5-8 mm long; outer bracts not wholly herbaceous, c. 2 mm long. Ray florets numerous; ligules white to pale purple, c. 1-2 mm long. Achenes subcylindric to ellipsoid, compressed, 4-5-ribbed, 1.5-2.2 mm long, with sparse antrorse hairs.

Similar Taxa

No similar species.

Flowering

Year-round

Flower Colours

Violet / Purple,Yellow

Fruiting

Summer to winter

Year Naturalised

1896

Origin

North America, possibly also Central and South America

Reason for Introduction

Unknown, seed or soil contaminant

Control Techniques

Can be controlled manually, mechanically or herbicidally depending on situation.

Life Cycle and Dispersal

Wind dispersed seed.

Attribution

Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA). Features description from Webb et al. (1988).

References and further reading

Webb, C.J.; Sykes, W.R.; Garnock-Jones, P.J. (1988). Flora of New Zealand Volume 4: Naturalised pteridophytes, gymnosperms, dicotyledons. Botany Division, DSIR, Christchurch.

Popay et al (2010).  An illustrated guide to common weeds of New Zealand, third edition.  NZ Plant Protection Society Inc, 416pp.

Johnson PN, Brooke PA (1989).  Wetland plants in New Zealand.   DSIR Field Guide, DSIR Publishing, Wellington. 319pp.

This page last updated on 27 Oct 2019