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Female inflorescence of <em>Garrya fremontii</em> Torrey, Fremont's silk tassel
Dylan O. Burge Duke University Biology Biology Durham North Carolina 27708 USA (919) 323-5447
Scientific Description/Explanation: The genus Garrya Dougl. ex Lindl. [See "Terms From Scientific Description," below, for explanations of terms in italics] (Garryaceae) contains 15 species of winter-blooming, wind-pollinated, dioecious evergreen trees and shrubs distributed in North America (including Mexico), Central America, and the Caribbean Islands. The genus Garrya is found only in the New World, but is closely related to the genus Aucuba, which is native to China and Japan. The genus Garrya is thought to represent a relatively recent introduction to the New World, which probably migrated from Asia over a high-latitude land-bridge sometime during the last twenty million years. Garrya fremontii is a widespread species that occurs from central California to Washington State. It is most abundant at middle and high elevations (1000-3000 meters) in parts of the Sierra Nevada Mountains, the Pacific Coast Ranges, and the Cascade Range. It occupies a diversity of habitats, from chaparral and oak woodland to coniferous forests. The plant in the photograph is part of a population of Garrya fremontii growing on Doe Mill Ridge in Butte County, California, about 15 kilometers north-northeast of the town of Chico. These plants are part of a dense chaparral community composed mainly of species of Arctostaphylos (manzanita) and Ceanothus. This community is strongly fire regulated, with fires occurring about every seven to ten years. Garrya fremontii, along with many other members of this chaparral community, survives fire by re-sprouting from a buried root-crown, or lignotuber. It also regenerates from seeds deposited in the soil seed-bank. Garrya fremontii is part of a complex of species from western North America, within which the species are very difficult to differentiate. Garrya fremontii intergrades morphologically with Garrya flavescens in the coast ranges of California, which may indicate that these two taxa are not distinct. In addition, preliminary results using DNA sequence data (see URL below) suggest that there is very little genetic variation among species of Garrya in California. Like all species in the genus, Garrya fremontii flowers during the late winter, long before most plants have begun their growing season. The flowers are born in pendulous inflorescences, as shown in the image, and have a unique, highly reduced structure. In female inflorescences the flowers are arranged in successive groups that are each partially surrounded by a bract. In the photograph, these bracts are obvious as the greenish, triangular flaps that cover the bases of the silky, developing ovaries. Opposite bracts sometimes fuse, forming a cup that surrounds multiple groups of flowers. Individual female flowers lack almost all vestiges of a corolla or calyx, although minute remnants of these structures are sometimes present near the base of the styles. The presence of these perianth remnants is usually taken as evidence that the ovaries of Garrya fremontii are inferior. The ovaries of all Garrya species are composed of two carpels, and thus produce two seeds. The styles of Garrya fremontii are characteristically elongated and thin, often recurving toward the inflorescence axis, which gives the appearance of a "handle-bar mustache." This character is clearly visible in the image, although some of the styles have dried up and broken off, as the inflorescence in the image is several weeks old and past the fertilization stage. Male inflorescences are not shown in the image, but male plants were present in the vicinity of the pictured plant. Male inflorescences are also morphologically reduced, and specialized for wind pollination. These adaptations include a special chamber formed from the distally fused perianth members that is thought to aid in preventing desiccation of the pollen. The male inflorescence is also less rigid than the female inflorescence, which enables it to flex with the wind currents. Most species of Garrya flower well before the time when potential pollinators are active, sometimes while snow is still on the ground, so scientists have inferred that they are wind pollinated. The fruits of Garrya fremontii mature in the fall, and are dark blue in color. It is not certain what the primary dispersal agent of this plant may be, but species of Neotoma (wood rats) are known to collect them. Overall, Garrya fremontii, and the genus Garrya in general, present an intriguing combination of highly derived morphological traits, unusual ecology, and potentially complex genealogical and geographical patterns going back to the Old World. Garrya also takes readily to cultivation, and several species and hybrids are popular landscape plants in the Western United States.
<font color="#666666">Garrya</font> - The scientific name of any organism should always be underlined or printed in italics. The scientific name of an organism always has two parts, the genus name (Garrya, for instance), and the species name (fremontii, for instance). Because of the parts of speech corresponding to these two words, and convention, the first is always capitalized, while the latter is never capitalized.
<font color="#666666">Dougl. ex Lindl</font> - In plant taxonomic treatments, papers, floras, labels, etc., the name of a plant taxon is often given along with the name of the authority for that taxon (the author of the taxon name). In the case of the genus Garrya, the authority is Lindley, who was the first to validly publish (sanction) the name Garrya, which had been proposed, but not validly published, by Douglas.
<font color="#666666">Dioecious</font> - Most plants have bisexual flowers, with male and female parts combined within the same structure. However, some taxa have the male and female parts separated into different flowers. If both female and male flowers occur on the same plant, then the species is known as monoecious. If the flowers are born on separate plants, analogous to the two-sex system of many animals, then the plant is known as dioecious.
<font color="#666666">DNA sequence</font> - DNA (Deoxyribonucleic acid) is the information-carrying molecule of living things. DNA, which encodes information for building proteins, is the basis for almost all of the characteristics of a given organism, as expressed during development. Scientists use DNA to gain insight into the history of life on earth, and the dynamics of living systems. This is possible because of the unique hereditary role of DNA, which accumulates errors in living organisms, some of which are passed on to subsequent generations. DNA can be extracted from living organisms and its code, or sequence, can be read using specialized techniques. This information may be used in a statistical fashion to infer the genealogy of a group of organisms, such as a genus or species of plant.
<font color="#666666">Inflorescence</font> - The reproductive part of a plant, including all flowers and the stems on which they are born, is called an inflorescence. There is considerable diversity in inflorescence structure among flowering plants. A daisy "flower," for instance, is really an inflorescence containing several hundred individual flowers.
<font color="#666666">Bract, carpel, ovary, corolla, calyx, perianth, style</font> - Most flowers are composed of four "whorls" of parts. (1) The female parts, or carpels, which each have an ovary as well as a stigma (the receptive surface for pollen) that is born on the end of a style. (2) The male parts, or stamens, which are made up of pollen-bearing anthers on the end of filaments. (3) The petals, which together are known as the corolla. (4) The sepals, which are typically green and collectively called the calyx. The calyx and corolla are together known as the perianth. All of these flower parts are attached to a receptacle, which is often born on the end of a stalk called the pedicel. This pedicel is often subtended by (found immediately above) a leaf-like organ called a bract. All of the amazing and beautiful diversity of flower morphology is simply variation on this theme of four whorls and subtending elements.
<font color="#666666">Inferior</font> - When the corolla and calyx become fused to the walls of the carpels so that the stamens, anthers, and stigmas appear anatomically above the ovary, rather than below it, then the ovaries of that flower are termed inferior. Normal ovaries are termed superior. An apple, for example, is derived from a fertilized flower with inferior ovaries. The perianth, stamens, and styles are often visible in the depression on the distal end of the apple (opposite the stem, or pedicel).
<font color="#666666">Distally</font> - In anatomical terms, an organ that is far from a point of reference is distal, while an organ that is near is proximal. Your hand, for instance, is on the distal end of your arm. These terms are used universally in discussions of both animal and plant anatomy.
<font color="#666666">Derived</font> - Genealogies of organisms are also known as phylogenies. Humans, apes, and monkeys, for instance, are all related, and the specific genealogical relationships between them, as inferred from morphological traits or DNA sequence variation, can be expressed as a branching, tree-like phylogeny, in which the earliest-branching lineages (those appearing lowest on the tree) are considered as ancestral, and the most recent, latest branching lineages are considered as derived.
Bremer, B., Bremer, K., Heidari, N., Erixon, P., Olmstead, R.G., Anderberg, A.A., Källersjö, M., & Barkhordarian, E. 2002. Phylogenetics of asterids based on 3 coding and 3 non-coding chloroplast DNA markers and the utility of non-coding DNA at higher taxonomic levels. Molecular Phylogenetics and Evolution 24: 274-301.
Dahling, G.V. 1978. Systematics and evolution of Garrya. Contributions from the Gray Herbarium of Harvard University 209: 1-104.
Eyde, R.H. 1964. Inferior ovary and generic affinities of Garrya. American Journal of Botany 51: 1083-1092.
Graham, A. 1999. The tertiary history of the northern temperate element in the northern Latin American biota. American Journal of Botany 86: 32-38.
Hileman, L.C., Vasey, M.C., & Parker, V.T. 2001. Phylogeny and biogeography of the Arbutoideae (Ericaceae): implications for the Madrean-Tethyan hypothesis. Systematic Botany 26: 131-143.
Liston, A. 2003. A new interpretation of floral morphology in Garrya (Garryaceae). Taxon 52: 271 276.
Oxelman, B., Yoshikawa, N., McConaughy, B.L., Luo, J., Denton, A.L., & Hall, B.D. 2004. RPB2 gene phylogeny in flowering plants, with particular emphasis on asterids. Molecular Phylogenetics and Evolution 32: 462-479.
Additional data
Vascular plant systematics Quick view
Botanical Name
Garrya fremontii
Common Name
Fremont's silk tassel
Location Area
Doe Mill Ridge, Butte County
Location State
Location Country
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