Geum macrophyllum
Geum glaciale
benoîte à grandes feuilles, bigleaf avens, large-leaf avens
glacier avens
30–110 cm, puberulent and hirsute or sparsely hirsute.
2–30 cm, densely pilose, hairs 2–5 mm.
basal 10–45 cm, blade interruptedly lyrate-pinnate, major leaflets 5–9, alternating with 4–15 minor ones, terminal leaflet usually much larger than major laterals;
cauline 2–12 cm, stipules ± free, 7–23 × 3–12 mm, blade lyrate-pinnate, pinnate, 3-foliolate, or simple and 3-lobed.
basal 3–10 cm, blade pinnate-pinnatifid, leaflets/lobes 11–23, terminal leaflet slightly larger;
cauline 1.4–2.5 cm, stipules adnate to leaf, indistinguishable from lobes, blade bractlike, not resembling basal, alternate, simple, 3-fid.
3–16-flowered.
1-flowered.
densely puberulent, sometimes with scattered longer hairs, sometimes stipitate-glandular.
densely pilose, eglandular.
erect;
epicalyx bractlets often absent, 0.5–2 mm;
hypanthium green;
sepals erect-spreading but soon reflexed, 2.5–5.5 mm;
petals spreading, yellow, obovate, broadly elliptic, or suborbiculate, 3.5–7 mm, longer than sepals, apex rounded.
erect;
epicalyx bractlets 6–9 mm;
hypanthium green;
sepals spreading-erect, 7–14 mm;
petals 5–9, spreading, yellow, obovate, orbiculate, or ovate, 10–20 mm, longer than sepals, apex rounded to emarginate.
sessile or on less than 1 mm stipes, puberulent.
sessile, silky.
geniculate-jointed, proximal segment persistent, 2.5–6 mm, apex hooked, sparsely to densely stipitate-glandular, distal segment deciduous, 1–2 mm, pilose in basal 1/3, hairs much longer than diam. of style.
wholly persistent, not geniculate-jointed, 18–30 mm, apex not hooked, pilose except distal 1–3 mm.
= 28.
Geum macrophyllum
Geum glaciale
Varieties 2 (2 in the flora).
Characters useful in recognizing specimens of Geum macrophyllum are yellow petals, epicalyx bractlets often absent, proximal style segment sparsely to densely stipitate-glandular, and fruiting receptacles puberulent. Across its broad North American range from Alaska to California and Nova Scotia, G. macrophyllum exhibits considerable variation. Based largely on the shape of the terminal leaflet of the basal leaves and the degree of dissection and shape of the divisions of the distal cauline leaves, P. A. Rydberg (1913b) distinguished three species within the range of variation treated here as one species. Basal leaves of G. macrophyllum in the strict sense (var. macrophyllum in this treatment) have relatively large reniform to rounded terminal leaflets and the distal cauline leaves are three-cleft into rhombic or cuneate lobes. The basal-leaf terminal leaflets of G. perincisum (= var. perincisum) are only slightly larger than the laterals and are deeply lobed into rhombic-obovate segments; the distal cauline leaves are dissected into oblanceolate divisions. Both basal and cauline leaves of G. oregonense (= var. perincisum) are intermediate between those of G. macrophyllum and G. perincisum. W. Gajewski (1955) crossed all three taxa under discussion and examined leaf morphology and cytology of the F1 and F2 hybrids. He concluded that they were distinct but not yet completely separated species. Fairly well correlated with the more dissected leaves of G. oregonense and G. perincisum is the presence of minute stalked glands on the pedicels. The treatment here follows H. M. Raup (1931) in recognizing two varieties of G. macrophyllum based more on pedicel glandularity than leaf morphology.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Flowers of Geum glaciale have from five to nine petals with seven being the most common. Other species of Geum nearly always have five petals, which is standard in most rosaceous genera. The sepals of G. glaciale are usually in two whorls for a total of about ten, and the bractlets are in two to three whorls. The exact number of epicalyx bractlets and sepals is made difficult to determine by the thick covering of hairs and because individual sepals and bractlets are sometimes deeply divided into two equal lobes.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Pedicels not glandular-puberulent; cauline leaves with distal simple and 3-lobed (divided less than 3/4 to base), lobes rhombic-oblong. | var. macrophyllum |
1. Pedicels glandular-puberulent; cauline leaves with distal 3-foliolate or simple and 3-lobed (divided almost to base), lobes oblanceolate to obovate. | var. perincisum |
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