Pterolepis glomerata
(false meadowbeauty)

Pictures

Picture	Title	Caption	Copyright
Title Habit Caption Pterolepis glomerata (false meadowbeauty); habit. Esplanada, Bahia, Brazil. October 2012. Copyright ©Alex Popovkin-2012, Bahia, Brazil/via wikipedia - CC BY 2.0	Habit	Pterolepis glomerata (false meadowbeauty); habit. Esplanada, Bahia, Brazil. October 2012.	©Alex Popovkin-2012, Bahia, Brazil/via wikipedia - CC BY 2.0
Title Flower Caption Pterolepis glomerata (false meadowbeauty); flower. Parque Nacional de Brasília, Brasília, Distrito Federal, Brasil. June 2011. Copyright ©João Medeiros-2011, Brasil/via wikipedia - CC BY 2.0	Flower	Pterolepis glomerata (false meadowbeauty); flower. Parque Nacional de Brasília, Brasília, Distrito Federal, Brasil. June 2011.	©João Medeiros-2011, Brasil/via wikipedia - CC BY 2.0
Title Habit Caption Pterolepis glomerata (false meadowbeauty); habit, showing stem and leaves. Brasil. October 2012. Copyright ©Alex Popovkin-2012, Bahia, Brazil/via wikipedia - CC BY 2.0	Habit	Pterolepis glomerata (false meadowbeauty); habit, showing stem and leaves. Brasil. October 2012.	©Alex Popovkin-2012, Bahia, Brazil/via wikipedia - CC BY 2.0

Identity

Preferred Scientific Name

• Pterolepis glomerata (Rottb.) Miq.

Preferred Common Name

• false meadowbeauty

Other Scientific Names

• Arthrostemma angusturense (Rich.) Naudin
• Arthrostemma angusturense DC.
• Arthrostemma brachyandrum Cham.
• Arthrostemma capitatum (Rich.) Naudin
• Arthrostemma glomeratum (Rottb.) Cham.
• Arthrostemma salzmannii Naudin
• Chaetogastra callichaeta Benth.
• Chaetogastra glomerata (Rottb.) Benth.
• Chaetogastra sherardioides DC.
• Osbeckia glomerata (Rottb.) DC.
• Osbeckia glomerata var. albiflora DC.
• Osbeckia maritima A. St.-Hil.
• Osbeckia sipaneoides DC.
• Pterolepis capitata (Rich.) Miq.
• Pterolepis hostmannii Steud.
• Pterolepis maritima (A. St.-Hil.) Cogn.
• Pterolepis paludosa Cogn.
• Pterolepis salzmanii (Naudin) Cogn.
• Pterolepis sipaneoides (DC.) Cogn.
• Rhexia angusturensis Rich.
• Rhexia capitata Rich.
• Rhexia glomerata Rottb.

Local Common Names

• Caribbean: balier blan; balye blam; herbe sure

Summary of Invasiveness

P. glomerata is up to 0.5 m tall and occurs in mesic to wet lowland forest, natural and disturbed savannas and boggy coastal grasslands in tropical regions of eastern South America and the Caribbean. It was introduced to Hawaii where it has naturalized and is known as an environmental weed. P. glomerata is classified as invasive because of its prolific seed production (>1000/m² per year), germination rate, rapid growth, early maturity, ability of fragments to root, asexual reproduction and seed dispersal by birds. P. glomerata displaces native vegetation through competition with a high risk score of 11 in the Weed Risk Assessment for the Pacific region (PIER, 2015).

Taxonomic Tree

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Spermatophyta
•             Subphylum: Angiospermae
•                 Class: Dicotyledonae
•                     Order: Myrtales
•                         Family: Melastomataceae
•                             Genus: Pterolepis
•                                 Species: Pterolepis glomerata

Notes on Taxonomy and Nomenclature

Pterolepis belongs to the Melastomeae, a large pantropical tribe. Melastomataceae comprise approximately 4,500 species and 150 genera from tropical and subtropical areas (Renner, 1993).

There have been some taxonomic revisions in the past for P. glomerata. P. glomerata was first collected between June 1755 and January 1756 by D. Rolander in Surinam. He described P. glomerata as new species of Rhexia. A. P. de Candolle (1828a,b) assigned new species for Pterolepis so as to reflect natural affinities, placing P. glomerata in Osbeckia L. De Candolle named this new section of Osbeckia ‘Pterolepis’ (Greek: with winged scales). Nowadays, Osbeckia is considered to be restricted to the paleotropics, while Pterolepis occurs in the neotropics.

Chamisso (1835) placed the 5-merous species of Pterolepis in Chaetogastra, while the 4-merous ones preferably should go in Arthrostemma. A dwarf form of P. glomerata thus was described as A. brachyandrum Cham. Bentham (1840), by contrast, disregarded floral mery and put P. glomerata (4-merous) into Chaetogastra. At the same time, Miquel (1840) decided that de Candolle’s section Pterolepis deserved generic rank in spite of the heterogeneity in habit and flower mery of the genus. Though he was only concerned with the Surinamese species, among them P. glomerata (Renner, 1994).

Macromorphologically Pterolepis closely resembles species in the African and Asian genera Antherotoma, Dissotis, Melastoma, and Osbeckia. The widespread species Osbeckia chinensis L.and O. cochinchinensis Cogn. for example, appear to be counterparts to P. glomerata, morphologically as well as ecologically (Renner, 1994).

Saint-Hilaire, one of the early collectors of Pterolepis in Brazil, described a littoral form of P. glomerata as Osbeckia maritima (Renner, 1994).

There are ten named varieties of P. glomerata, indicating significant variation. These are: angustifolia, angusturensis, brachyandra, glaziovii, longifolia, martiana, microphylla, peruviana, saldanhaei and sherarioides (The Plant List, 2013).

Description

The following is adapted from Renner (1994), Gordon (1998), Broome et al. (2007) and PIER (2015):

Profusely branched, erect, suffrutescent herb or subshrub up to 0.5 m tall. Stem and distal branchlets obscurely quadrangular, moderately strigose.

Leaves are regularly distributed along the stem, spreading, often with a second, precocious pair in the axils of the first. Leaves are ovate to oblong-ovate or elliptic, 1.4-4.5 cm long, 0.6-1.6 cm wide, 3-nerved, both surfaces sparsely to moderately strigose, margins entire or obscurely serrulate, apex acute, base obtuse to rounded, petioles 1-5 mm long.

Flowers can be pink, purple or white. Plants from the Guianas and eastern Venezuela frequently have white petals. Usually 3-5 flowers up to 10 inch bracteate, terminal glomerules, bracts and bracteoles ovate to lanceolate, 3.5-6 mm long, 1-2.5 mm wide at base, persistent, cilate; hypanthium covered with simple and stalked-stellate or branched hairs; calyx lobes triangular or oblong-ovate, 4-7.5 mm long, ca. 2 mm wide at base, ciliolate; petals obovate, ± obliquely truncate, 10-15 mm long, 10-14 mm wide; larger anthers pink, 3-4 mm long, connective prolonged 0.25-0.5 mm, with a 2-lobed appendage ca. 0.5 mm long, smaller anthers yellow, 2.5-3.5 mm long, with connective and appendage somewhat shorter but otherwise as in larger anthers.

Fruiting hypanthium is 4-6 mm long, 2-5 mm wide. Seeds are ca. 0.5 mm long and width is ca. 0.35 mm, weight of seed is 19 μmg.

Plant Type

Distribution

The majority of the Pterolepis species occur in central Brazil but P. glomerata is more widespread. It stretches across the central, northern and eastern regions of South America, from Paraguay to Venezuela, where the climate is tropical. It has been reported as present in Bolivia, French Guiana, Guyana, Suriname and Venezuela (Almeda, 1990; Roskov et al., 2015; USDA-ARS, 2015).

It has also been reported as native to the Lesser Antilles in the Carribbean, including the islands of Dominica, Grenada, Guadeloupe, Martinique, St. Lucia, St. Vincent and Grenadines (Roskov et al., 2015; USDA-ARS, 2015), as well as Puerto Rico and the Dominican Republic (Greater Antilles) and Trinidad and Tobago (South American shelf) (Almeda, 1990; Roskov et al., 2015; USDA-ARS, 2015).

The Encyclopedia of Life (2015) states that P. glomerata is also regularly occurring in the USA, but there are no other sources that mention occurrences in the USA.

P. glomerata has been naturalized and is invasive to a number of islands of Hawaii. However, there are some contradictory reports on which islands of Hawaii it occurs. According to PIER (2015)P. glomerata is present on Hawaii Island, Kauai Island, Oahu Island, Molokai Island and Lanai Island. Roskov et al. (2015) also mention the first four islands, but instead of Lanai Island they state that P. glomerata is present on Wailau Island.

Distribution Table

The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Risk of Introduction

P. glomerata received a high risk score of 11 in a risk assessment for the Pacific region (PIER, 2015), indicating the dangers posed by further introduction.

Habitat

The majority of the Pterolepis species occur in central Brazilian cerrado vegetation (a type of savanna that is characteristic of southeastern and central Brazil).

P. glomerata is adapted to tropical climate and occurs from sea level up to 1000 m. Its elevation range suggests that it may be able to tolerate cooler temperatures at higher elevations (PIER, 2015). P. glomerata occurs in mesic to wet lowland forest, especially around the forest edge, natural and disturbed savannas and boggy coastal grasslands that in Brazil are called ‘restinga’. It tends to invade mesic to wet disturbed habitats and trail margins (Almeda 1990; Renner, 1994; Graveson, 2012; PIER, 2015).

The aluminium tolerance in P. glomerata is a trait that possibly contributes to its wide distribution in acid soils throughout the neotropics. Also its introduction and naturalization in areas far from its site of origin could possibly be explained by this trait (Olivares et al., 2013).

Habitat List

Biology and Ecology

Genetics

The chromosome number is 2n = 36 (Wagner et al., 2015).

Reproductive Biology

P. glomerata produces viable seeds and can reproduce by vegetative fragmentation as well. The minimum generative time is 1 year (PIER, 2015). The floral sexuality is hermaphrodite (Ramirez and Brito, 1990) and the flowers are pollinated by small and medium-sized bees that collect pollen. There are no reports on detailed observations on the pollination or breeding systems of Pterolepis.

Fruiting starts gradually while the plant is still flowering, the capsules releasing the seeds over several weeks (Renner, 1994). P. glomerata produces seeds prolifically (>1000/m² per year) (PIER, 2015).

There are contradictory reports on the longevity of P. glomerata. According to Renner (1994) it is an annual herb. Others report that it is a perennial herb (Ramirez and Brito, 1990; USDA-ARS, 2015).

Climate

Latitude/Altitude Ranges

Rainfall

Soil Tolerances

Soil drainage

• impeded
• seasonally waterlogged

Soil reaction

• acid
• very acid

Special soil tolerances

• infertile
• other

Natural enemies

Means of Movement and Dispersal

Natural Dispersal

Propagules are dispersed by water (PIER, 2015). According to Gerrish (1978) the seeds have a great dispersability.

Vector Transmission (Biotic)

Propagules are dispersed by birds. Propagules are also likely to be dispersed unintentionally, because plants grows in heavily trafficked areas (PIER, 2015). Occasionally seeds can also be spread in mud on birds' feet (Renner, 1994).

Pathway Causes

Pathway Vectors

Impact Summary

Environmental Impact

Impact on Habitats

P. glomerata is known as an environmental weed in Hawaii, USA (PIER, 2015). If no measures are taken against invasive species like P. glomerata, then these species will alter and eventually destroy the natural composition of the ecosystems in Hawaii and will seriously limit the functionality of the watershed (Wood, 2000).

Impact on Biodiversity

Viola kauaensis var. wahiawaensis is known only from the Wahiawa Mountains of Kauai Island, Hawaii. This species is not known to have occurred beyond its current range. Fewer than 100 individuals are known to remain in Kanaele Swamp (often referred to as Wahiawa Bog), an open bog surrounded by low shrubs at an altitude of 640 m. P. glomerata competes with V. kauaensis var. wahiawaensis and is a current threat to this species (US Fish and Wildlife Service, 1998). V. kauaensis var. wahiawaensis is listed as Endangered under the US Endangered Species Act (ESA).

Also Viola helenae is only growing in the Wahiawa Mountains of Kauai Island. Its habitat is also affected by P. glomerata and the species is also listed as endangered under the US ESA (U.S. Fish and Wildlife Service, 2006).

Other species that are affected by P. glomerata and listed as endangered under the US Endangered Species Act are Pteris lidgatei and Sanicula purpurea on Oahu Island, Hawaii (US Fish and Wildlife Service, 2007; 2009).

Threatened Species

Risk and Impact Factors

• Proved invasive outside its native range
• Fast growing
• Has high reproductive potential
• Reproduces asexually

• Reduced native biodiversity
• Threat to/ loss of endangered species
• Threat to/ loss of native species

• Competition - monopolizing resources
• Rapid growth

Similarities to Other Species/Conditions

Osbeckia chinensis and O. cochinchinensis are widespread species that, morphologically as well as ecologically, appear to be counterparts to P. glomerata. Similarities among these groups consist in the presence of branched intercalycine emergences, details of staminal morphology, setose ovary apices, habit, leaf shape, and indumentum. Precocious axillary shoots are characteristic of P. glomerata (Renner, 1994).

Prevention and Control

Biological control

Cryptorhynchus melastomae (Coleoptera: Curculionidae) is a stem boring weevil from Costa Rica under evaluation as a potential biological control agent for the invasive tree Miconia calvescens (Melastomataceae) in Hawaii. No-choice and multi-choice tests with adult weevils revealed a host range restricted to melastomes (family Melastomataceae), all of which are invasive weeds in Hawaii. Adult weevils also fed on P. glomerata. The weevil feeds externally on foliage and stems, and larvae bore stems (Raboin et al., 2011a).

Syphraea uberabensis (Coleoptera: Chrysomelidae) is a South American flea beetle whose adults and larvae feed externally on foliage and soft stems of Tibouchina spp. Multi-choice behavioral tests with adult beetles and no-choice tests with adults and larvae indicated a host range restricted to several species within the tribe Melastomeae, all of which are invasive weeds in Hawaii. P. glomerata proved to be one of the species that were preferred by the beetle for feeding and egg laying. P. glomerata is also a suitable host for the complete life cycle of S. uberabensis. In Hawaii, S. uberabensis may prove to be an effective control against the weedy melastome species (Raboin et al., 2011b).

Euselasia chrysippe (Lepidoptera: Riodinidae) is a gregarious defoliating caterpillar that has been tested as a biological control for several species, among them P. glomerata. The damage caused by the caterpillar was measured in an ‘average damage assessment’: from no damage (0) to severe defoliation (5). The average damage of P. glomerata was 3.3 (Puliafico and Johnson, 2014).

Meganola brunellus (formerly known as Rlayncopalpus brunellus, Selca brunella or Nola brunella) is a leaf-skeletonizing caterpillar. It was found causing obvious foliar damage to some roadside specimens of P. glomerata on the island of Hawaii (Conant and Hirayama, 2001).

References

Almeda F, 1990. Melastomataceae. In: Manual of flowering plants of Hawaii [ed. by Wagner, W. L. \Herbst, D. R. \Sohmer, S. H.]. Honolulu, Hawaii, USA: University of Hawaii Press, Bishop Museum, 903-917.

Bentham G, 1840. Enumeration of plants collected by Mr Schomburgk in British Guiana. Melastomaceae. Hooker's Journal of Botany, 2:286-315.

Broome R; Sabir K; Carrington S, 2007. Plants of the Eastern Caribbean. Online database. Barbados: University of the West Indies. http://ecflora.cavehill.uwi.edu/index.html

Candolle APde, 1828. Melastomaceae. An essay of the natural system of the vegetable kingdom, 3 (Melastomaceae. Prodromus systematis naturalis regni vegetabilis, 3). Paris, France: Treuttel et Wurtz, 99-202.

Candolle APde, 1828. Memory on the family Melastomataceae (Memoire sur la famille des Melastomacees). Paris, France: Treuttel et Wurtz.

Chamisso A, 1835. The plants in the scouting expedition Romanzoffiana and herbariis observe royal berolinensibus. Melastomaceae americanae. (De plantis in expeditione speculatoria Romanzoffiana et in herbariis regiis berolinensibus observatis. Melastomaceae americanae.) Linnaea, 9:428-460.

Conant P; Hirayama C, 2001. Two new host records for Rhyncopalpus brunellus hampson (Lepidoptera: Arctiidae). In: Proceedings of Hawaiian Entomological Society, 35. 145-146.

Encyclopedia of Life, 2015. Encyclopedia of Life. www.eol.org

Gerrish G, 1978. Factors for controlling the distribution of exotic plants in the Ko'olau Mountains, O'ahu. In: Proceedings of the Second Conference in Natural Sciences Hawaii Volcanoes National Park; 1978 June 1-3; Honolulu [ed. by Smith, C. W.]. Honolulu, Hawaii, USA: University of Hawaii at Manoa, 120-124.

Gordon E, 1998. Seed characteristics of plant species from riverine wetlands in Venezuela. Aquatic Botany, 60(4):417-431.

Graveson R, 2012. Plants of Saint Lucia. http://www.saintlucianplants.com

Miquel FAG, 1840. Commentarii phytographici. Leiden, Netherlands: S and J Luchtmans.

Olivares E; Benitez M; Pena E; Colonnello G, 2013. Aluminium accumulation and nutrients in Pterolepis glomerata, Desmoscelis villosa, and Rhynchanthera grandiflora in palm swamp communities. Botany, 91(3):202-208.

PIER, 2015. Pacific Islands Ecosystems at Risk. Honolulu, USA: HEAR, University of Hawaii. http://www.hear.org/pier/index.html

Puliafico KP; Johnson MT, 2014. Processionary progress in developing biocontrol of Miconia calvescens. XIV International Symposium on Biological Control of Weeds; Kruger National Park, South Africa, March 2014., South Africa 42.

Raboin E; Brooks S; Calvert F; Johnson MT, 2011. Managing Miconia calvescens in Hawaii: biology and host specificity of Cryptorhynchus melastomae, a potential biological control agent. In: Proceedings of the XIII International Symposium on Biological Control of Weeds, Waikoloa, Hawaii, USA, 11-16 September 2011 [ed. by Wu, Y. \Johnson, T. \Sing, S. \Raghu, S. \Wheeler, G. \Pratt, P. \Warner, K. \Center, T. \Goolsby, J. \Reardon, R.]. Volcano, Hawaii, USA: USDA Forest Service, Pacific Southwest Research Station, Institute of Pacific Islands Forestry, 247.

Raboin E; Souder S; Johnson MT, 2011. Biological control for management of cane Tibouchina and other weedy melastome species in Hawaii. In: Proceedings of the XIII International Symposium on Biological Control of Weeds, Waikoloa, Hawaii, USA, 11-16 September 2011 [ed. by Wu, Y. \Johnson, T. \Sing, S. \Raghu, S. \Wheeler, G. \Pratt, P. \Warner, K. \Center, T. \Goolsby, J. \Reardon, R.]. Volcano, Hawaii, USA: USDA Forest Service, Pacific Southwest Research Station, Institute of Pacific Islands Forestry, 248.

Ramirez N; Brito Y, 1990. Reproductive biology of a tropical palm swamp community in the Venezuelan Llanos. American Journal of Botany, 77(10):1260-1271.

Renner SS, 1993. Phylogeny and classification of the Melastomataceae and Memecylaceae. Nordic Journal of Botany, 13(5):519-540.

Renner SS, 1994. A revision of Pterolepis (Melastomataceae: Melastomeae). Nordic Journal of Botany, 14(1):73-104.

Roskov Y; Abucay L; Orrell T; Nicolson D; Kunze T; Culham A; Bailly N; Kirk P; Bourgoin T; DeWalt RE; Decock W; Wever A De, 2015. Species 2000 & ITIS Catalogue of Life. Leiden, Netherlands: Naturalis Biodiversity Center. http://www.catalogueoflife.org/col/

The Plant List, 2013. The Plant List: a working list of all plant species. Version 1.1. London, UK: Royal Botanic Gardens, Kew. http://www.theplantlist.org

US Fish and Wildlife Service, 1998. Kauai II: Addendum to the Recovery Plan for the Kauai Plant Cluster. Portland, Oregon, USA: US Fish and Wildlife Service, 84 pp.

US Fish and Wildlife Service, 2006. Endangered and threatened wildlife and plants; initiation of 5-year reviews of 70 species in Idaho, Oregon, Washington, Hawaii and Guam: Viola helenae. Federal Register, 71(69). 18345-18348.

US Fish and Wildlife Service, 2007. Endangered and threatened wildlife and plants; initiation of 5-year reviews of 71 species in Oregon, Hawaii, Commonwealth of the Northern Mariana Islands and territory of Guam: Pteris lidgatei. Federal Register, 72(45). 10547-10550.

US Fish and Wildlife Service, 2009. Endangered and threatened wildlife and plants; initiation of 5-year reviews of 103 species in Hawaii. Federal Register, 74(49). Honolulu, Hawaii, USA 11130-11133.

US Fish and Wildlife Service, 2010. Endangered and threatened wildlife and plants; determination of endangered status for 48 species on Kauai and designation of critical habitat. Federal Register, 75(70):18960-19165. [50 CFR Part 17, RIN 1018-AV48.] http://www.gpo.gov/fdsys/pkg/FR-2010-04-13/pdf/2010-1904.pdf

USDA-ARS, 2015. Germplasm Resources Information Network (GRIN). Online Database. Beltsville, Maryland, USA: National Germplasm Resources Laboratory. https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysearch.aspx

Wagner WL; Herbst DR; Lorence DH, 2015. Flora of the Hawaiian Islands website. Washington DC, USA: Smithsonian Institution. http://botany.si.edu/pacificislandbiodiversity/hawaiianflora/index.htm

Wood KR, 2000. Personal observations and vascular plant checklist. Kauai, Hawaii: National Tropical Botanical Garden.

Contributors

31/01/2016 Original text by:

Ymkje van de Witte, Consultant, Netherlands

Distribution Maps