Hardy kiwifruit (Invasive Plants of Maryland)

Hardy kiwifruit

Actinidia arguta

Description ¹⁰

Climbing shrubs, large, deciduous. Branchlets glabrous or rarely puberulent, tomentose when young, 7-15 cm; second-year branches grayish brown, glabrous, lenticels absent when young, small and inconspicuous when old; pith white to brown, lamellate. Petiole pinkish brown, 3-6(-10) cm, glabrous, sometimes rusty tomentose or setose; leaf blade abaxially green, adaxially dark green, usually ovate to broadly ovate to suborbicular, sometimes ovate-oblong, 6-12 × 5-10 cm, membranous to papery, abaxially glabrous to rusty tomentose to strigillose especially on midvein and lateral veins, barbate in axils of lateral veins or not, adaxially glabrous, midvein and lateral veins conspicuous abaxially, subconspicuous adaxially, lateral veins 5-7 pairs, straight or arcuate-ascending, anastomosing, veinlets reticulate, subconspicuous abaxially, inconspicuous adaxially, base rounded to cordate, rarely broadly cuneate, symmetrical or oblique, margin sharply serrate, apex abruptly acuminate. Inflorescences cymose, axillary or lateral, 1-7-flowered, brown to pale brown tomentose; peduncles 7-10 mm; pedicels 0.8-1.4 cm; bracts linear, 1-4 mm. Flowers greenish yellow or white, 1.2-2 cm in diam. when fully open. Sepals 4-6, ovate to oblong, 3.5-5 mm, margin ciliate, both surfaces glandular-tomentose, or abaxially slightly puberulent or glabrous. Petals 4-6, cuneate-obovate to orbicular-obovate, 7-9 mm. Filaments silky, 1.5-3 mm; anthers black or dark purple, oblong, 1.5-2 mm, sagittate at base. Ovary bottle-shaped, 6-7 mm, glabrous; styles 3.5-4 mm. Fruit greenish yellow or purple-red when mature, globose to oblong, 2-3 cm, rostrate or inconspicuously so, glabrous, lenticels and persistent sepals absent. Seeds ca. 2.5 mm. Fl. Apr, fr. Aug-Oct. 2n = 58, 116*, 174, 232.

Controversy over invasiveness in the northeastern United States ¹¹

Actinidia arguta has been cultivated by hobbyists, and more recently commercially, in the northeastern United States since at least the early 1900s with no significant impact on the region's forests noted, until recently. Due to rampant overgrowth and "complete domination of mature trees" at sites western Massachusetts and Coffin Woods, Long Island, New York, A. arguta vines of unknown genotype and provenance are now reported by groups including Mass Audubon and Vermont Invasives to be invasive. Whether such localized sites indicate an invasive risk for the region as a whole is controversial, given the long history of this widely distributed and cultivated species in the northeastern United States. Since successful invasions of non-native species can occur gradually over time, however, these reported sites warrant further investigation and suggest the need for more widespread monitoring.

Currently, the USDA Forest Service Section 3B Eastern Region lists A. arguta in Category 4 Plants for local concern and monitoring. These plants are non-native species that occur locally in the region. By their assessment, it is not currently known if it can be especially invasive, but the species was recommended for future monitoring. The Massachusetts Invasive Plant Advisory Group lists A. arguta as a species that did not meet the criteria at that time, citing a lack of evidence or deficiency of data on its reproductive ability and potential escape from cultivation.

National distribution ¹²

United States

Origin: Exotic

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

Sources and Credits

(c) Bahamut Chao, some rights reserved (CC BY-NC-ND), https://www.flickr.com/photos/bahamutzero/823849415/
(c) anonymous, some rights reserved (CC BY-NC), http://data.rbge.org.uk/images/32268/700
(c) anonymous, some rights reserved (CC BY-NC), http://data.rbge.org.uk/images/32270/700
(c) Sten Porse, some rights reserved (CC BY-SA), https://upload.wikimedia.org/wikipedia/commons/4/43/Actinidia-arguta-fruits.jpg
(c) anonymous, some rights reserved (CC BY-SA), https://upload.wikimedia.org/wikipedia/commons/1/13/Weiki01.jpg
(c) anonymous, some rights reserved (CC BY-SA), https://upload.wikimedia.org/wikipedia/commons/a/a8/Weiki02.jpg
(c) Erin Greunke, some rights reserved (CC BY-NC), uploaded by Erin Greunke
(c) voluntaryist, some rights reserved (CC BY-NC), uploaded by voluntaryist
(c) Alexander Ganse, some rights reserved (CC BY-NC), uploaded by Alexander Ganse
(c) Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, MO, 63110 USA, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/4973500
(c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Actinidia_arguta
(c) NatureServe, some rights reserved (CC BY-NC), http://eol.org/data_objects/29054088

More Info

Range Map

iNat Map

‹ › ×

Hardy kiwifruit

Description 10

Controversy over invasiveness in the northeastern United States 11

National distribution 12