Vitex rotundifolia
(beach vitex)

Preferred Scientific Name

• Vitex rotundifolia L. f.

Preferred Common Name

• beach vitex

Other Scientific Names

• Vitex agnus-castus var. ovata Kuntze
• Vitex ovata Thunberg
• Vitex repens Blanco
• Vitex rotundifolia forma albescens Linnaeus f.
• Vitex rotundifolia forma albiflora S. S.
• Vitex rotundifolia forma rosea Satomi
• Vitex trifolia subsp. litoralis Steenis
• Vitex trifolia var. obovata Bentham
• Vitex trifolia var. ovata Makino
• Vitex trifolia var. simplicifolia Chamisso
• Vitex trifolia var. unifoliolata Schauer

International Common Names

• English: creeping vitex; roundleaf chastetree
• French: gatilier à feuilles simples
• Chinese: dan ye man jing; manjingzi

Local Common Names

• China: viticus fructus
• Japan: hamagô
• Korea, Republic of: man hyung ja
• USA/Hawaii: hinahina kolo; kolokolo kahakai; manawanawa; mawanawana; pohinahina; polinalina

EPPO code

• VIXRO (Vitex rotundifolia)

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Spermatophyta
•             Subphylum: Angiospermae
•                 Class: Dicotyledonae
•                     Order: Lamiales
•                         Family: Lamiaceae
•                             Genus: Vitex
•                                 Species: Vitex rotundifolia

The genus Vitex was designated by C. Linnaeus Sr. in 1753. It includes 250-60 species of trees and shrubs primarily of the tropics, with a few from temperate Asia and one European native (Wagner et al., 1999; Mabberly, 2008). Although sometimes placed in the family Verbenaceae, the genus Vitex is a clear member of the Lamiaceae based on its laterally attached ovules and rbcL and ndhF molecular sequences; characters which are considered monophyletic for the Lamiaceae (Labiatae) (Judd et al., 2002). Within the Lamiaceae, Vitex is placed in the polyphyletic subfamily Viticoideae along with Gmelina, Callicarpa, Premna, Cornutia and other relatives (Judd et al., 2002).

C. Linnaeus Jr. described V. rotundifolia based on type material from Japan. It is related to, but distinct from and thereby not synonymous with Vitex trifolia L. (Wagner et al., 1999).

Description from Munir (1987), Flora of China Editorial Committee (2016) and Wagner et al. (1999):

A prostrate shrub 10-40 (-90) cm high, spreading to about 10-20 m diameter.

Stems prostrate to creeping, rooting at the nodes. Young branches silky-tomentose. Branches terete or obscurely 4-sided when mature.

Leaves mostly 1-foliolate, rarely a few 2- or 3- 5-7 (-9) foliolate, sessile or with short petioles. Blade obovate-oval, broadly oblong-elliptic, orbicular, or obovate-spatulate, 2.5-5 cm long, 1.5-3 cm broad; base tapering to rounded, margin entire, apex abruptly subacuminate to rounded; abaxial (lower) surface velvety to minutely silky tomentose, adaxial (upper) surface usually pale dull green and pubescent; pair of nerves 4-6.

Inflorescence mostly abbreviate, terminal thyrse borne on small side-branches, 3-10 (-13) cm long, 1-2.5 cm wide; densely tomentose; cymes with short peduncules, usually branched, arranged in a pyramidal panicle.

Flowers zygomorphic with short pedicels; pedicels densely glandular and tomentose, 0.5-2 mm long; bracteoles linear, 1-2.5 mm long. Calyx tube cylindrical, 3-4 mm long, 2-3 mm diam. at the top, 5-ribbed outside with 5 short teeth at the top; glandular and silky-tomentose outside, glabrous within.

Corolla purplish-mauve to lilac-blue; tubular below, tube abruptly spreading, 2-lipped and 5-lobed above; glandular and silky-tomentose outside, villous inside the tube and on the lower half of the large anterior lobe of the lower-lip; the anterior lobe broadly elliptic or almost orbicular in outline, glabrous in the upper inner half and along the periphery outside, 3-5 (-6) mm long, 3-5 mm broad; the two lateral lobes more or less oblong-elliptic or elliptic-ovate, 2-3 (-4) mm long, 1.5-3 (-3.5) mm broad at the base; the two lobes of the upper lip oblong-ovate, 2-3 (-4) mm long, 1.5-3 (-3.5) mm broad. Tube cylindrical below, gradually enlarged upwards, almost twice the length of the calyx, 4-7 mm long, 2-4 mm broad at the top.

Stamens exserted, connate to the corolla-tube; filaments filiform, the anterior pair 7-9 mm long, the lateral pair 6.5-8 mm long; anthers elliptic-oblong in outline, ± 1 mm long, lobes oblong, free and divergent in the lower half.

Ovary globose, glabrous, densely glandular all over, 1-1.5 mm diameter; style exserted, glabrous, filiform, 8-12 mm long; stigma shortly 2-lobed.

Fruit a globose fleshy drupe. Green when fresh, bluish purple to black when ripe, becoming dark-brown when dry; glabrous, glandular all over; 4-5.5 mm long, 5-6.5 mm diameter; fruiting calyx glandular and tomentose outside, glabrous within; 5-toothed, 5-6.5 mm diameter. The seeds are difficult to remove from the fruit.

The Arboretum of North Carolina State University, USA, originally recommended V. rotundifolia to the nursery industry where it became available in southeastern USA during the mid to late 1980s. There it was promoted for stabilizing shore dunes while at the same time providing unusual flowers and foliage to the landscape. It was planted by homeowners and incorporated into revegetation programs, especially those that followed extensive hurricane damage of frontal dunes in 1989 (Cousins et al., 2010a). Clonal growth and occasional self-starting, adjacent seedlings were observed to contribute to the unexpectedly rapid expansion of planted patches. Spontaneous populations in isolated areas of barrier islands and regional beaches began to occur from seeds and/or stems carried by longshore drift and coastal currents (Murren et al., 2014).

In 2001, V. rotundifolia was first vouchered as naturalized in the USA, from Georgetown County, South Carolina (Hauser et al., 2009). Within ten years, a survey discovered plants at 246 sites in South Carolina and at 621 sites in North Carolina (Cousins et al., 2010a). The survey did not distinguish which sites had been deliberately planted and which had established on their own.

In 2012, V. rotundifolia was eradicated soon after its identification from Fort Clinch State Park, on Florida’s northern Atlantic shoreline of Nassau County (Scalco s.n. [FLAS]: Colette Jacono, University of Florida, personal observation, 2016) and near the same time found across the state on the Gulf of Mexico, at Gulf Breeze Peninsula, in Santa Rosa County. Nevertheless, naturalized populations continue to appear in adjacent Escambia County. 22 populations have been located on Santa Rosa Island and one at Perdido Bay (Sanson 1 [FLAS]; FLEPPC, 2014) as they do on Atlantic beaches south to Flagler and Volusia County, Florida where land managers continue to find and manage plants (FLEPPC, 2014). Inland to Putnam County, central Florida, the species has been known to hang on for years in an abandoned garden, with no indication of invasive tendencies (Whitten 4072b [FLAS]).

Soil drainage

• free

Soil reaction

• alkaline

Soil texture

• light

Special soil tolerances

• infertile
• saline

Primary dispersal of V. rotundifolia is naturally by ocean currents and intentionally by humans.

Natural Dispersal

Estuarine river currents, ocean waves, offshore and deep water ocean currents. A thick water repellent cuticle on fruits helps aid dispersal by ocean currents. Ocean currents are believed to be responsible for the pervasiveness of V. rotundifolia throughout the Pacific. It occurs on many volcanic islands, including those that have existed for only a short time (Cousins et al., 2010b).

Vector Transmission (biotic)

Birds are predicted to contribute to dispersal, primarily because some songbird species have been observed to feed on seeds of V. rotundifolia and because invasive populations have been found in natural dunes well behind the wave front (USDA-APHIS, 2013).

Accidental Introduction

Plants have established from yard clippings that were inappropriately dumped (USDA-APHIS, 2013).

Intentional Introduction

Intentional dispersal of V. rotundifolia has been by humans, primarily those owning shoreline property and planting on dunes as a sand binder and/or as an ornamental.

Along the Atlantic coastal beaches of southeastern USA, large revenues have been spent in eradicating and/or managing invasive populations. Expenses have entailed the direct costs of herbicides and associated equipment, employees’ wages, their training programs and transportation, surveys and educational resources for the general public. Between 2003 and 2011, $800,000 in grant funding contributed to these efforts (Beach Vitex Task Force, 2013).

V. rotundifolia was listed as a noxious weed in North Carolina in 2009 (Cousins et al., 2010b) but is not listed on the current State-listed Noxious Weeds List (USDA-NRCS, 2016).

Impact on Habitats

Severely alters native habitat by dominating primary dune areas with dense, sprawling, perennial, woody cover (Beach Vitex Task Force, 2013). Thickets can reach 15-60 cm high.

Occludes photosynthetically active radiation (PAR) from reaching the sand surface. Approximately 90% of PAR is excluded by populations of V. rotundifolia as opposed to 20-40% of PAR by stands of sea oats (Uniola paniculata) a native grass which can be crowded out by V. rotundifolia (Westbrooks and Madsen, 2006; Cousins et al., 2010a).

Encourages dune erosion and reduced dune profile due to its non-fibrous taproot which extends vertically with minimal branching. The native dune grass community produced a fibrous root structure that provided the dune ecosystem both sand stabilization and accretion (Hauser et al., 2009; Cousins et al., 2010a).

Induces hydrophobicity in the sand substrate due to accumulated deposits of cuticular alkanes deposited from overlying leaves and fruits (Cousins et al., 2009). Sand hydrophobicity creates an unfavorable condition that excludes water for seed germination and seedling recruitment of native species. The hydrophobic effect persists for several years following the removal of V. rotundifolia (Cousins et al., 2009).

Impact on Biodiversity

Dominating monocultures of V. rotundifolia greatly reduce the native floristic diversity of grasses and herbaceous plants through shading, physical occlusion, and the development of hydrophobic conditions that inhibit native seedling regeneration (Cousins et al., 2009).

The tangle of woody branches formed by V. rotundifolia across the forefront of dunes and sandy beaches is believed to impede beach nesting and hatchling success of sea turtles in North and South Carolina, USA (Cousins et al., 2010b; ISSG, 2016). The Carolinas are home to a number of sea turtle species which are either US Federally Endangered or Threatened, including: loggerhead (Caretta caretta), green turtle (Chelonia mydas), Kemp's Ridley (Lepidochelys kempii)leatherback (Dermochelys coriacea), and hawksbill (Eretmochelys imbricate)(Cousins et al., 2010b; ISSG, 2016).

Sea-beach amaranth (Amaranthus pumilus) is a US Federally Threatened plant species that can be outcompeted by V. rotundifolia (Westbrooks and Madsen, 2006). A. pumilus is an effective sand binder, building small dunes where it grows on sparsely vegetated lower foredunes and upper strands of non-eroding beaches. It does not grow on well-vegetated sites and so cannot tolerate competition by V. rotundifolia.

Encroachment of V. rotundifolia into critical nesting habitats of migratory shorebirds, such as the US Federally Endangered piping plover (Charadrius melodus) (US Fish and Wildlife Service, 2009), remains an impending threat to species requiring open sand for nesting.

Beach residents and beach-goers of southeastern USA have shared an alarmed concerned over the spread of this species because of its demonstrated ability to limit their access to recreation, mainly by covering beach entry trails and occluding sandy beaches with woody mats of low growing shrubbery (Beach Vitex Task Force, 2013).

• Proved invasive outside its native range
• Has a broad native range
• Abundant in its native range
• Pioneering in disturbed areas
• Highly mobile locally
• Long lived
• Fast growing
• Has high reproductive potential
• Has propagules that can remain viable for more than one year
• Reproduces asexually
• Has high genetic variability

• Negatively impacts tourism
• Reduced amenity values
• Reduced native biodiversity
• Threat to/ loss of endangered species

• Allelopathic
• Competition - shading
• Rapid growth
• Rooting

• Highly likely to be transported internationally deliberately

Economic Value

Micro propagation methods have been developed for the mass production of explants to be used in commercial cultivation aimed at growing fruits for traditional Asian medicine (Park et al., 2004). Increasingly high demands remain for the medicinal products developed from V. rotundifolia in China (Hu et al., 2007).

Social Benefit

Pharmacological studies have demonstrated that flavonoids isolated from V. rotundifolia, have anti-inflammatory, antitumor, and analgesic properties (Kobayakawa et al., 2004; Bae et al., 2013; Gao and Chen, 2015). A recent example demonstrated that the flavonoid vitexicarpin significantly reduced vascular inflammation, which leads to atherosclerosis, by inhibiting adhesion molecules that injure the vascular endothelial cells (Lee et al., 2012).

Environmental Services

In Hawaii, USA, V. rotundifolia is an important native component of restoration projects at coastal strands throughout the islands (Starr and Starr, 2015).

Draft datasheet under review