American and Asian Jumpseed in North America

Asian Jumpseed, Persicaria filiformis

Cultivars of the Asian Jumpseed, Persicaria filiformis ‘Painter’s Palette’, ‘Lance Corporal’, ‘Variegata’ and ‘Bat Wings’ are escaping from cultivation in the eastern United States and becoming naturalized. As early as 2017 and 2018, I noted many escapes in the Washington, DC area and began alerting people then to the nomenclatural issues, how to identify it and it's serious invasive potential. It has since spread more widely and become a serious pest in several areas of the northeast.

Morphologically, Persicaria filiformis and its cultivars can be distinguished from the American species Persicaria virginiana by the elliptic leaves that are widest at or above the middle and with persistent purple markings, whereas Persicaria virginiana has ovate leaves, widest below the middle and purple markings only on young leaves. There are other subtle differences one can learn with practice. The American Jumpseed occasionally has pink flowers, so that alone is not enough to distinguish the species.

These introduced, artificial hybrids may interbreed with the indigenous Persicaria virginiana, eroding its genetic integrity and possibly compromising fitness and survival of this important indigenous American plant. The aggressive growth of the Asian Jumpseed also threatens other biodiversity by forming large, monocultural stands that crowd out other species.

Persicaria filiformis (Thunb.) Nakai, Asian Jumpseed is sister to the American Jumpseed. They may share a common ancestor, but millenia of isolation, drifting continents and changing vegetation patterns caused the two species to diverge genetically, anatomically and chemically. But some taxonomists don't consider these differences enough to divide the species and treat them as two varieties of one species or just one species (under the oldest name, Persicaria virginiana). The one-species concept prevailed several decades ago and is often used in older literature and in the horticulture trade. Today there is ample data from multiple lines of evidence and strong support for separating the two as distinct species (Park et al., 1992; Mun & Park, 1995; Suh et al., 1997).

American Jumpseed, Persicaria virginiana

Persicaria virginiana (L.) Gaertn. American Jumpseed is a perennial herb to 1.5 m tall, from knotty rhizomes; stems are erect, slender and few-branched; ocreae strigose or tomentose, the apices ciliate; leaf blades ovate, 5–17 × 2–10 cm, reduced apically, the bases rounded, the apices acute to acuminate, strigose above and below, the margins setose; inflorescences to 45 cm long, very slender; flowers solitary or 2–3 per ocreolate fascicle; tepals 4, white, greenish white or rarely pink; achenes brown with hooked, persistent style. 2n=44.

The species is found across the eastern United States (and southern Canada), east of the 100th meridian, from southern Minnesota to Texas and Quebec to Florida, disjunct in central Mexico; found in rich deciduous forests, floodplain forests, dry woodlands, thickets; flowering July to October.

Synonyms include Polygonum virginianum, Tovara virginiana, Antenoron virginianum, Tovara virginiana f. rubra, Tovara virginiana var. glaberrima

The deflexed pedicels are under strong tension and when disturbed can propel the fruit 3–4 m from the plant (hence the name Jumpseed). The persistent hooked styles aid in animal dispersal. The plants are easy to recognize when young by the relatively large, ovate leaves and often very prominent maroon chevron that disappears as the leaves age. Small flies, bees and wasps are observed visiting the flowers and Robber Flies use the plants to hunt prey. Herbivory by Sawflies in the genus Allantus creates holes in the leaves (https://www.inaturalist.org/observations/52429526).

Anecdotally, I have noticed that nearly every American Jumpseed has holes in the leaves, made by a native Sawfly. This Sawfly appears rarely to feed on the Asian Jumpseed. If the latter displaces the native species or corrupts it's genetic integrity, the viability of the Sawfly could be compromised along with its host plant. Let's just hope the technocrats in the invasive species industrial complex don't get the terrible idea to bring over an Asian Sawfly to "manage" this plant.

I recommend supporting the indigenous species and all its ecological benefits and removing the cultivar wherever found.

Except where explicitly stated, the words and research in this article are entirely my own. The facts belong to everyone. Please acknowledge that you heard it here first.

References
Suh, Y., S. Kim and C.W. Park. 1997. A phylogenetic study of Polygonum sect. Tovara (Polygonaceae) based on ITS sequences of nuclear ribosomal DNA. Journal of Plant Biology 40: 47–52.

Park, CW., M.G. Lee and H. Shin. 1992. A systematic study of Polygonum sect. Tovara (Polygonaceae): analysis of morphological variation. Korean Journal of Botany 35: 385–392.

Mun, J.H. and C.W. Park. 1995. Flavonoid chemistry of Polygonum sect. Tovara (Polygonaceae): a systematic survey. Plant Systematics and Evolution 196: 153–159.

Publicado el octubre 26, 2020 04:40 TARDE por danielatha