Physalis philadelphica Lam. 1786

Sennikov, Alexander & Lazkov, Georgy, 2022, The first checklist of alien vascular plants of Kyrgyzstan, with new records and critical evaluation of earlier data. Contribution 2, Biodiversity Data Journal 10, pp. 80804-80804 : 80804

Physalis philadelphica Lam. 1786

Physalis philadelphica Lam., Encycl. 2(1): 101 (1786).

Physalis philadelphica Physalis ixocarpa Physalis philadelphica subsp. ixocarpa

Diagnosis

In Central Asia, P. philadelphica has been commonly confused with P. angulata . It differs from the latter by ovate-lanceolate leaves on shorter petioles (Fig. 20 ), intensely yellow corollae with prominent dark brown spots at the base (Fig. 21 ), shorter pedicels, and fruiting calyces indistinctly (Fig. 22 ) angled in fruit ( Terrones et al. 2020).

Distribution

Native distribution

Native to Central America.

Secondary distribution

Widely cultivated as a fruit crop. Introduced in many countries of North America, Europe, Africa, Asia, Australia. Archaeophyte in North America ( González-Pérez and Guerrero-Beltrán 2021), neophyte elsewhere.

In arid areas of Asia, the species was introduced to Turkey in the 1990s as a weed of irrigated cotton fields ( Bükün et al. 2002), where it became invasive and quickly gained the top status among other weeds ( Bükün 2004). In other arid territories, this species is not invasive.

Distribution in Central Asia

Reported from Kazakhstan, Kyrgyzstan and Uzbekistan for the first time here.

In Kazakhstan, the species was observed for the first (and only) time in 2019, in a damp place at Jabağyly Village, Turkestan Region ( Plantarium 2021).

In Kyrgyzstan, it was found for the first time in Bishkek, in 2015.

In Uzbekistan, the species was originally recorded in 1929 and 1930 as a weed of cotton cultivation ( Kovalevskaya 1961, Khassanov et al. 2020), but this record was erroneously based on misidentified specimens of P. angulata (see discussion under that species). Since 2008, the species was repeatedly collected as a ruderal plant in Tashkent ( Plantarium 2021). Besides, recently it was noted (albeit with a low abundance) as a weed in Tashkent Region: on late carrot fields in Oqqoʻrgʻon District ( Axmedov and Narbaev 2019), on tomato fields in Qibray District ( Axmedov et al. 2020) and along margins of maize fields in Qibray District ( Plantarium 2021). All recent records were misidentified as P. angulata .

Distribution in Kyrgyzstan

Northern Tian-Shan (Fig. 23 ).

The species was first recorded by Georgy Lazkov in Bishkek City in 2015, as a few scattered individuals along Toktogul Street and a large population (ca. 20 flowering individuals) on the southern margin of the city. The scattered individuals withered quickly, whereas the fate of the large population was not studied. Further on, one individual was observed in flower in Sokuluk Village in 2021. The plants usually occurred in places with regular water supply, along irrigation ditches.

Ecology

Open or partly shaded places on humid, fertile soils in the native distribution area; roadsides, fields, field margins, ditches and riversides, dumps and ruderal places in the secondary distribution area.

In arid areas, the species depends on the availability of water supply ( Bükün et al. 2002).

Biology

Annual or short-lived perennial ( Rydberg 1896), with a taproot.

Plants of Physalis philadelphica are self-incompatible ( Mulato-Brito et al. 2007). This genetic feature reduces the chances for reproduction of single plants or small colonies derived from a single source of introduction.

Notes

Physalis ixocarpa is sometimes separated from P. philadelphica s. str., at the rank of species or subspecies (e.g. Rydberg 1896, Stace 2010). The alleged differences are in the size of corolla (5-10 mm in diam. in P. ixocarpa , 10-25 mm in diam. in P. philadelphica ), with corresponding differences in the size of calyx and fruit. These dimensional characters match the infraspecific variability observed in Mexico ( Zamora-Tavares et al. 2014), part of the native distribution area of P. philadelphica , thus evidencing that the two putative taxa are synonyms. The taxonomy of this species is still unsettled, with some authors being reluctant to accept a broader concept (e.g. Pretz and Deanna 2020).

The plants observed in Kyrgyzstan were small-flowered, thus corresponding to P. ixocarpa .

Physalis philadelphica has been an important crop in Mexico since pre-Columbian times, and now it is cultivated globally as 'tomatillo' for its edible fruits ( Small 2011). The long history of cultivation, as well as the presence of wild, cultivated and weedy populations already in the country of origin, may account for its high level of morphological variability ( Zamora-Tavares et al. 2014).

Introduction to Kyrgyzstan

Period of introduction

Neophyte.

The first record from Kyrgyzstan was dated 2015, thus falling within the period of the independence.

Pathways of introduction

Transport - Contaminant: Seed contaminant.

In Kyrgyzstan, the species is sometimes cultivated in private gardens and sold privately in marketplaces (Lazkov, pers. obs.), but its direct escape from cultivation is considered highly unlikely. Its occurrences on roadsides and waste ground in populated places suggest the arrival with contaminated grain or fodder. No further dispersal was noticed.

In Uzbekistan, the species with certainly arrived with contaminated seed material, as indicated by its occurrence on fields. A wide variety of contaminated seed material (carrots, tomato, maize) indicates its North American origin and multiple sources of introduction.

In Russia, the species was introduced in the European part with garden seeds, as a weed of flower beds and vegetable gardens, recorded in the Middle Volga Region in the 1990s ( Rakov et al. 2011). Its earliest record in Siberia (Novosibirsk, dated 1944) comes from potato fields ( Ebel et al. 2015).

In the USA, the species is cultivated for fruits and frequently escapes from cultivation, becoming established along roadsides and field margins ( Sullivan 2004). In Kenya, its original introduction was intentional as a green manure crop that caused a local invasion ( Cunningham-van Someren 1957). In the British Isles, the species originated with grain, wool and food refuse ( Clement and Foster 1994); it was also known as a contaminant of bird seed ( Hanson and Mason 1985).

Further dispersal in other countries was registered as occurring with animals ( Cunningham-van Someren 1957) and water ( Bükün et al. 2002). Its riverbed occurrence in Spain ( Gómez-Bellver et al. 2016) seems to be connected with this type of dispersal.

Source of introduction

Presumably North America.

Invasion status

Casual; ephemeral or locally persisting. The species may become established in places with regular water supply; so far, no long-term survival has been observed.

Evidence of impact

Agriculture - no impact (so far, not recorded on fields, although recent surveys are lacking). Native ecosystems - no impact (not found outside populated places). Urban areas - minor impact (casual occurrence as a ruderal plant).

Trend

Increasing (observed).

The species has been noticed in Kyrgyzstan only recently, as a newcomer. Its regular recent occurrence as a weed or ruderal plant in Uzbekistan may suggest further spreading also in Kyrgyzstan. Its recent introduction and subsequent expansion in Turkey ( Economou et al. 2016) indicates that the species is potentially invasive in regularly irrigated areas.

Figures

Figure 20. Physalis philadelphica in Bishkek (single plant) (photo by G. Lazkov, 15 August 2015).

Figure 21. Physalis philadelphica in Bishkek (small-sized flower) (photo by G. Lazkov, 15 August 2015).

Figure 22. Physalis philadelphica in Bishkek (immature fruits) (photo by G. Lazkov, 15 August 2015).

Figure 23. Distribution of Physalis philadelphica in Kyrgyzstan.