Geum macrophyllum
Rosaceae tribe Colurieae
benoîte à grandes feuilles, bigleaf avens, large-leaf avens
30–110 cm, puberulent and hirsute or sparsely hirsute.
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.
alternate, sometimes opposite (Geum), pinnately compound or simple;
stipules persistent, ± free or ± adnate to petiole;
venation pinnate or palmate.
3–16-flowered.
densely puberulent, sometimes with scattered longer hairs, sometimes stipitate-glandular.
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.
perianth and androecium perigynous;
epicalyx bractlets absent or present;
hypanthium funnelform, saucer- to cup-shaped, or obconic to obcampanulate;
torus usually enlarged;
carpels (2 or)3–250(–450), styles terminal (subterminal in Waldsteinia), distinct;
ovules 1 or 2, basal, superposed.
sessile or on less than 1 mm stipes, puberulent.
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.
aggregated achenes;
styles persistent, sometimes deciduous (Waldsteinia), elongate, sometimes hooked, glabrous or hairy, rarely plumose.
Geum macrophyllum
Rosaceae tribe Colurieae
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.)
Genera 4, species ca. 60 (4 genera, 22 species in the flora).
Waldsteinia is recognized as distinct from Geum in this treatment, while D. Potter et al. (2007) included the former in the latter. Names are provided for users who would prefer to include Waldsteinia within Geum, as supported by molecular data (J. E. E. Smedmark and T. Eriksson 2002).
The base chromosome number for Colurieae is x = 7. Except for Fallugia, the genera of Colurieae are host to Phragmidium rusts. C. Kalkman (2004) stated that two ovules had been reported for Fallugia but that he observed only one, which would accord better with membership in Colurieae.
(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 |
1. Shrubs, 10–20(–35) dm; leaves simple; flowers all pistillate, all staminate, or staminate with terminal one bisexual. | Fallugia |
1. Herbs or subshrubs, 0.2–12 dm; leaves simple, sometimes lobed, or ternately or pinnately compound; flowers bisexual | → 2 |
2. Subshrubs; inflorescences: flowers solitary. | Sieversia |
2. Herbs; inflorescences 1–18-flowered, open cymes or panicles | → 3 |
3. Plants subscapose or leafy-stemmed; tori hemispheric to cylindric; carpels (2–)20–250(–450); fruiting styles persistent, elongating, hooked or not. | Geum |
3. Plants scapose; tori not evident; carpels 3–7; fruiting styles deciduous, not hooked. | Waldsteinia |
- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
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MI Flora, 
MN Wildflowers, 
PNW Herbaria, 
SW CO Wildflowers, Turner Photog. 
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