Solidago altissima, the tall goldenrod[5] or late goldenrod,[6] is a North American species of goldenrod in the family Asteraceae which is widespread across much of Canada, the United States, and northern Mexico. It is common in much of its range and fairly tolerant of landscapes which have been disturbed by humans. It has become naturalized in many parts of the world.
Description
Solidago altissima is one to two meters (40 to 80 inches) in height with fine hairs on the stem. The leaves are located along the stem, not in a rosette near the ground. One plant can produce as many as 1500 small yellow flower heads in a large conical array. The involucres of the main subspecies (S. a. subsp. altissima) are usually 3–4 millimeters, whereas those of S. a. subsp. gilvocanescens are usually 2–3 mm.[6]
Solidago altissima has a base number of nine chromosomes(x = 9). Diploid, tetraploid, and hexaploid plants with respective chromosome counts of 18, 36, and 54 have been reported among the two subspecies.[6]
Taxonomy
Solidago altissima has diploid, tetraploid, and hexaploid populations as well as morphological variations which have generally led to classifying it into two subspecies. Roughly speaking, these subspecies can be identified as being from the eastern and western parts of the North American continent. At least in the Midwest, it is common to have plants of different ploidy interspersed, with little apparent tendency for one type to dominate even a fairly local geographical area.[7]
Solidago altissima subsp. altissima is the autonym.[2]
Solidago altissima subsp. gilvocanescens (Rydb.) Semple[2] differs from the autonym by range and has a smaller involucre size.[6]
Distribution and habitat
S. altissima is widespread across much of Canada, the United States, and northern Mexico.[6] It is common in much of its range and fairly tolerant of landscapes which have been disturbed by humans.[7]
S. a. subsp. gilvocanescens (Rydb.) Semple[2] is in western Canada and Ontario. In the United States, it is only east of the Mississippi River in Illinois and is then distributed west through the Great Plains states. In Mexico, it overlaps S. a. subsp. altissima except in the west.[4]
Ecology
Reproduction
Solidago altissima is self-incompatible, meaning that the pollen from one plant cannot pollinate the female flower parts of the same plant.[7]
Herbivory defense
Galls
This species is host to the following insect induced galls:
S. altissima produce cysteine and serine protease inhibitors as an inducible defense against herbivory.[11] These protease inhibitors can negatively affect the digestive system of herbivores slowing growth and reproduction making them an effective mean of resistance.[12] The production of these inhibitors is costly and can vary between populations, possibly being lower in areas that are not subject to as much predation.[13][11]
Ducking
Ducking has been found to occur in populations of S. altissima as a defense mechanism. This is a process in which certain individuals within a population will bow until their tops point downward in an effort to hide from egg laying insects. This bowing is temporary, only occurring during the egg laying period of species that use the plant as a host, such as goldenrod gall fly (Eurosta solidaginis) and the goldenrod bunch gall midge (Rhopalomyia solidaginis).[14] Insect species inject their eggs into goldenrod buds causing spherical swelling on the plant known as a gall.[15] Members of the population with this "candy-cane" phenotype experience a lower chance of hosting eggs and having galls formed by these herbivores.[14]
Gall of the goldenrod gall fly (Eurosta solidaginis) on Solidago altissima in Guelph, Ontario
Individuals that undergo ducking are in the minority, with most individuals staying upright through growth and flowering.[14] This genetic phenomenon, of two stem growth phenotypes within one species, is a form of dimorphism. Though ducking provides S. altissima with the benefit of being able to avoid damage from insect oviposition, the fact that it occurs in a low number of individuals in populations suggests that there is a cost to having this trait, possibly preventing it from becoming the major phenotype.[16]
Conservation
As of 2022[update], NatureServe listed Solidago altissima as Secure (G5) worldwide. It is Imperiled (S2) in Maine and New Brunswick and Critically Imperiled (S1) on Prince Edward Island. Its global status was last reviewed by NatureServe in May 2016.[1]
^USDA, NRCS (2014). "Solidago altissima". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 18 November 2015.
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Halverson, Kristy; Heard, Stephen B.; Nason, John D.; Stireman, John O. (2008). "Origins, distribution, and local co-occurrence of polyploid cytotypes in Solidago altissima (Asteraceae)". American Journal of Botany. 95 (1): 50–58. doi:10.3732/ajb.95.1.50. PMID21632314.