Botanical Information about Eriogonums

Family: Polygonaceae (go to BONAP Polygonaceae Listing at http://www.csdl.tamu.edu/FLORA/bonapfams/bonxxplg.htm for a complete list of all the taxa in the genus eriogonum in North America north of Mexico)

In order to get a listing of eriogonums by state(s) go to the USDA PLANTS DATABASE. at http://plants.usda.gov/plants

General Descriptions

-Gray's Manual of Botany -

"Flowers Perfect, involucrate; involucre 4-8 toothed or lobed, usually many flowered; the more or less exserted peicels intermixed with scarious bracts. Caylx 6 parted or cleft, colored and persistant about the achene. Stamens 9, upon the base of the Caylx. Styles 3; stigmas capitate. Achene triangular. Embryo straight and axial, with foliaceous cotyledons. -Leaves entire, without stipules. N. Am. (mostly western). (Name from the Greek erion, wool, and gonu, knee, from the wooly stems and leaves and swolen joints of the plants)"

My translation (pease remember I and not a botanist or plant taxonomist.): the flowers have both male and female parts. There is a cup-shaped base (the involucre) containing many flowers. i.e. each little pom-pom is made up of many flowers coming out of one cup. The little stems of the flowers usually stick out of the cup-shaped base and there may be some dry little bits sticking out also. There are 6 colored parts that appear to be "petals" that hang on and dry, (this how the petals and the sepals are refered to collectively when they look very similar; individually the colored parts are refered to as tepals). These "petals" dry up as the flower ages, but they hang on and hide the hard little seeds. There are nine pollen bearing anthers (the male parts) attached to the base of the flower. There are three female parts (styles) and the pollen receiving parts of the styles (the stigmas) are grouped together, head-like. The seeds are three sided. The embryo inside the seed is straight , aligned in the center and has small seed leaves that look like tiny leaves folded up inside too. The leaves have a smooth edge without teeth or lobes (they are entire) and there are no little leaflike structures at the point where the leaf stem is connected to the plant stem (stipules).

-Flora of the Pacific Northwest, Hitchcock & Cronquist - (Contributed by James Reveal)

"Invols camp to turbinate, 3-10 lobed or toothed, 2-several fld, solitary or in clusters, terminal, capitate, umbellate or cymose; peds stipelike in some; perianth white to yellow, rose or purple, glab to pubescent, 6-parted at base;Stamens 9, pistils 3-carpellary; sigmas mostly capitate; ann to per herbs or sub shrubs with alternate to whorled, entire, gen +/- tomentose, extipiate lvs. (Gr erion, wool, and gonu, knee, refering to the wooly nodes and sts.) Dwarf spp. are excellent rock garden subjects e Cas (East of the Cascade Mtns); grazing value slight."

Glossary For our Eriogonum pages - (Paraphrased from various field manuals, including "Gray's Manual of Botany", "Flora of the Pacific Northwest" and "A Utah Flora"

• bract - A reduced leaf , found below a flower.
• calyx - Outer whorl of flower parts; made up of all the sepals.
• capitate - A head-like grouping of plant structures, In Eriogonums the infloresence is called capitate if it is a single ball-like group of flowers.
• corolla - Inner whorl of floral parts; made up of all the petals.
• entire - A leaf is said to be entire if it has a smooth edge (i.e. has no teeth or lobes.)
• inflorescence - The collective term for the flower cluster of any plant.
• involucre - The cup-shaped base containing many flowers, it may be fused as in Eriogonum or consist of leafy bracts. In Eriogonum each little pom-pom is made up of many flowers coming out of one cup or involucre . Generally it is any structure which surrounds the base of another structure.
• glabrous - Without hairs.
• lanceolate - Lance like, much longer than it is wide.
• pedicel - The stalk of a single flower.
• petal -One of the second whorl of flower parts, generally colored and useful for attracting pollinators
• perianth - The collective term for the caylx and corrolla, especially if they are alike. There are 6 colored parts that appear to be "petals" that hang on and dry, (these are really segments of the outer part of the flower, the calyx and are called sepals). These "petals" dry up as the flower ages, but they hang on and hide the hard little seeds.
• sepal - One of the first or outermost whorl of flower parts, sometime colored and similar to the petals but more often green, leafy and reduced in size when compared to the petals.
• stipe -The stalk of any plant structure.
• umbel - A flattened inflorescence in which the florets are borne on stems that appear to come from one point. The outer flowers open before the inner ones.
• umbellate - arranged in umbels.

Return to Jan & Mike Slater's HomePage