New insights into the pollen morphology of the genus <i>Gunnera</i> (Gunneraceae)

Wanntorp, Livia; Praglowski, Joseph; Grafström, Elisabeth

doi:10.1080/00173130310016473

Cited by 14 publications

(7 citation statements)

References 16 publications

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“…The pollen grains of G. tinctoria are two‐celled at anthesis (Wilkinson & Wanntorp ). Gunnera tinctoria possesses a plesiomorphic type of pollen (type 2; Wanntorp, Praglowski & Grafström ), which is characterized by round and equidimensional lumina encircled by muri that are generally thicker than the diameter of the lumina (Wanntorp, Dettmann & Jarzen ).…”

Section: Floral and Seed Charactersmentioning

confidence: 99%

“…The earliest pollen record of Gunnera ( Tricolpites reticulatus ) is from the Turonian ( c . 90 Ma) in South America (Wanntorp, Praglowski & Grafström ). Wanntorp et al .…”

Section: Historymentioning

confidence: 99%

“…Gunnera pollen is highly distinctive, tricolpate, suboblate and spheroidal (see Jarzen 1980;Wanntorp, Praglowski & Grafström 2004; Fig. 3).…”

Section: Floral and Seed Charactersmentioning

confidence: 99%

“…Gunnera is one of the oldest living angiosperm genera (Jarzen 1980), with a fossil history that is remarkably well documented and relatively continuous, from the Early Cretaceous to the present (Schrank 1984;Jarzen 1980;Jarzen & Dettmann 1989). The earliest pollen record of Gunnera (Tricolpites reticulatus) is from the Turonian (c. 90 Ma) in South America (Wanntorp, Praglowski & Grafström 2004). Wanntorp et al (2001) and Wanntorp, Wanntorp & Rutishauser (2003) showed that Gunnera can be considered of Gondwanan origin and was widespread and abundant in North America from the Late Cretaceous to the Eocene (80-50 Ma), although its distribution has retreated over time, probably due to climatic and environmentally related changes (Jarzen 1980;Osborne & Sprent 2002;Osborne & Bergman 2009), particularly increases in aridity and the disappearance of inland seas and seaways that were common during the Cretaceous period (Osborne & Sprent 2002).…”

Section: T a X O N O M I C H I S T O R Ymentioning

confidence: 99%

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Biological Flora of theBritishIsles:Gunnera tinctoria

Gioria

2012

Journal of Ecology

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Summary1. This account presents information on all aspects of the biology of Gunnera tinctoria (Molina) Mirb. (G. chilensis Lam.; G. scabra Ruix & Pav.; G. pilosa Kunth) that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the standard framework of the Biological Flora of the British Isles: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, history and conservation. 2. Gunnera tinctoria is a gynomonoecious, clonal, perennial herb that is naturalized in parts of Britain, becoming invasive in parts of Ireland and, more recently, Scotland. It occurs where winter temperatures are mild, and precipitation and humidity are high. Gunnera tinctoria is native to South America, predominantly in the Andean region of Chile and Colombia, and probably in parts of Argentina, ranging from sea level to c. 2000 m a.s.l. 3. Typical habitats in Britain and Ireland include stream and river banks, lake and pond margins, coastal cliffs, as well as disturbed areas, such as roadsides, quarries and ditches. In its native range it occurs predominantly on the banks of rivers and streams, on coastal cliffs and within canopy gaps or at the margins of temperate-humid rain forests. 4. Gunnera tinctoria occurs on a variety of substrates, mainly on alluvial or colluvial soils derived from volcanic material or on thin gley soils of marine origin. In Ireland, it occurs naturally on soils with a pH ranging from 4.6 to 6.2 and has been cultivated in soils with a pH up to 7. Soil moisture content and soil organic matter vary greatly, although it rarely colonizes highly organic soils such as peat. It is susceptible to even mild water deficits at all stages of development, and its seedlings are also sensitive to waterlogged conditions. 5. Gunnera tinctoria produces large numbers of seeds and also spreads clonally, by a horizontal rhizome system. It is wind pollinated, although insect pollination has been reported in New Zealand. Seeds are likely to be predominantly water and/or bird dispersed. In its invasive range, it can form a large and persistent soil seed bank. Recruitment from seeds seems to be important for its initial establishment, while vegetative propagation is the main means of expansion, leading to dense clonal stands. Long-distance seed dispersal seems to be central to the colonization of new areas, although the transport of vegetative propagules may also be important. 6. Gunnera tinctoria is a strong competitor in its invasive range, particularly in wet, humid environments. Its competitive ability arises from its large stature, the persistence of its seeds and rhizomes and a capacity for fixing nitrogen through a unique intracellular symbiosis with cyanobacteria (Nostoc) that may be particularly important for supporting the rapid growth of established plants early in the spring.

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Section: Floral and Seed Charactersmentioning

confidence: 99%

“…The earliest pollen record of Gunnera ( Tricolpites reticulatus ) is from the Turonian ( c . 90 Ma) in South America (Wanntorp, Praglowski & Grafström ). Wanntorp et al .…”

Section: Historymentioning

confidence: 99%

“…Gunnera pollen is highly distinctive, tricolpate, suboblate and spheroidal (see Jarzen 1980;Wanntorp, Praglowski & Grafström 2004; Fig. 3).…”

Section: Floral and Seed Charactersmentioning

confidence: 99%

Section: T a X O N O M I C H I S T O R Ymentioning

confidence: 99%

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Biological Flora of theBritishIsles:Gunnera tinctoria

Gioria

2012

Journal of Ecology

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“…In Early Cretaceous fossils muri tend to be rounded-triangular and, therefore, the tips are less apparent. Since muri tips are observable in other families such as Gunneraceae (Wanntorp et al, 2004b) we do not consider them a diagnostic feature for Platanus. Basically, any pollen with a reticulum consisting of muri with triangular crosssection has the potential to form muri tips.…”

Section: Modern and Fossil Pollen Of Platanaceaementioning

confidence: 99%