Erigeron lilacinus (Sennikov & Kurtto) Sennikov 2020

Sennikov, Alexander N. & Lazkov, Georgy A., 2021, The first checklist of alien vascular plants of Kyrgyzstan, with new records and critical evaluation of earlier data. Contribution 1, Biodiversity Data Journal 9, pp. 75590-75590 : 75590

Erigeron lilacinus (Sennikov & Kurtto) Sennikov 2020

Erigeron lilacinus (Sennikov & Kurtto) Sennikov, Wulfenia 27: 2 (2020) - Erigeron annuus subsp. lilacinus Sennikov & Kurtto, Memoranda Soc. Fauna Fl. Fenn. 95: 47 (2019).

Diagnosis

In the group of Erigeron annuus s.l., E. lilacinus can be distinguished by its broader cauline leaves with more prominent teeth, pale lilac ray flowers, and involucres with hairs 0.8-1.2(1.5) mm long ( Sennikov and Kurtto 2019).

Distribution

Native distribution

North America (south-eastern Canada, north-eastern and eastern USA).

Secondary distribution

Neophyte in Europe and Asia.

In Eastern (Tropical) Asia, the occurrences of this species were known from Taiwan and Vietnam ( Sennikov et al. 2020). Both records previously reported from Nepal ( Sukhorukov 2015) also belong to E. lilacinus because of the lilac ray florets and coarsely dentate leaves.

The presence of the species in Central Asia is reported for the first time here. The distribution in other Asian countries has not been studied yet.

Distribution in Central Asia

First reported from Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan here.

In Uzbekistan, the species was first recorded by Alexander Sukhorukov in 2001 at the entrance to the Botanical Garden in Tashkent, where it occurred abundantly on ruderal places ( Seregin 2021). Tulkin Tillaev (and Alim Gaziev) also recorded this species in 2012 from ruderal places in Ulug'bek District of Tashkent City ( Plantarium 2021). The species is considered casual but locally persisting, on the way to naturalisation.

In Tajikistan, the species was previously reported as E. annuus [s.l.] ( Nobis et al. 2017). The plants were collected in 2007 ( Nobis et al. 2017) and observed in 2016 ( Plantarium 2021) along the streets, probably introduced as weeds of ornamental cultivation.

In Kazakhstan, the species is known from ruderal places and as a weed of flower beds in Almaty City. Two recent records are known: from the area situated close to the Botanical Garden and the National University, by Ruslan Nurkhanov in 2020 ( iNaturalist 2021), and from unspecified vicinities of the city in the Transili Alatau, by Igor Syazhkin in 2010 ( Plantarium 2021). The oldest record from the same city ( Tulaganova 1993), which was published as E. annuus [s.l.], has not been verified.

Distribution in Kyrgyzstan

Northern Tian-Shan.

The species is known from two populated places. In Bishkek, it has been recorded since the 1980s as having escaped from cultivation and then as fully naturalised in the Botanical Garden of the National Academy of Sciences (I. Popova, pers. comm.). Besides, recently it was found in two more places in Bishkek, by Galina Chulanova in 2015 (ca. five flowering individuals) on street lawns situated near the Botanical Garden ( Plantarium 2021) and by Georgy Lazkov in 2020 (ca. 10 individuals) on flower beds situated close to the Panfilov Park (Fig. 7 ), and also recorded from one place in a popular resort area along the northern side of Lake Ysyk-Köl, where it was observed by Galina Chulanova in 2011 ( Plantarium 2021). The latter area is known for numerous introductions of ornamental plants.

Ecology

Prairies and meadows in the native distribution area; artificial meadows, ruderal places and cultivated lands in the secondary distribution area.

Biology

Annual or biennial.

Introduction to Kyrgyzstan

Period of introduction

Neophyte.

In the Botanical Garden, the species was intentionally introduced in the 1970s and became established in the 1980s, during the late Soviet period. The species was unintentionally introduced in the 2000s (first recorded in 2011), during the period of the independence of Kyrgyzstan.

Pathways of introduction

Transport - Contaminant: Contaminant nursery material. Escape from confinement: Botanical garden.

In agreement with observations of Sennikov and Kurtto (2019), in Kyrgyzstan, Erigeron lilacinus was recently found in places of cultivation of ornamental plants or on artificial lawns. Consequently, we consider the species to have arrived with contaminated seed of ornamental plants or nursery material.

The record in the Botanical Garden in Bishkek has a different origin. In that place, the species was intentionally introduced for experimental cultivation in the 1970s (erroneously as " Conyza canadensis ") but quickly spread out of control and became established already during the 1980s. Currently, it is fully naturalised in the Garden but is still kept within its limits, except for a few cases of intentional introduction or unintentional secondary dispersal to private gardens (I. Popova, pers. comm.).

Invasion status

Casual, temporarily persisting or locally established, not invasive. So far, we have no evidence that the species formed stable populations rather than short-lived local colonies in the places of its accidental introduction, and no further dispersal from those places was observed. However, Erigeron lilacinus has recently become abundant in man-made habitats (especially fallow and abandoned fields) in Central Russia (Sennikov, pers. obs.) and may, therefore, become invasive also in Kyrgyzstan. Its population in the Botanical Garden is locally naturalised and may potentially serve as a source of invasion in the future, as evident from some occasional instances of secondary dispersal.

Evidence of impact

Agriculture - no impact (not recorded in crop production areas). Native ecosystems - no impact (restricted to populated places). Urban areas - minor impact (very rare weed of ornamental gardens and street lawns, also as a ruderal plant).

Trend

Increasing (observed).

Figures

Figure 7. Erigeron lilacinus on flower beds in Bishkek (photo by G. Lazkov, 11 June 2020).