Washington Flora Checklist
A Checklist of the Vascular Plants of Washington State
Hosted by the University of Washington Herbarium


Checklist » Saxifragaceae
Saxifragaceae   (Saxifrage Family)

Notes: FNA8: "Classification of Saxifragaceae has been varied and controversial (e.g., A. Cronquist 1981; H. G. A. Engler 1930; J. Hutchinson 1973; G. K. W. Schulze-Menz 1964b; A. L. Takhtajan 1997; R. F. Thorne 1992). Molecular phylogenetic data (D. R. Morgan and D. E. Soltis 1993; Soltis et al. 1993, 2001; Angiosperm Phylogeny Group 1998, 2003) reveal that genera of Saxifragaceae in the broad sense are allied with at least ten separate, often distantly related families of flowering plants. These data also suggest that Saxifragaceae in the narrow sense as treated here consists of about 38 genera worldwide, equivalent to subfamily Saxifragoideae, one of the 15 subfamilies recognized by Engler and one of the 17 recognized by Schulze-Menz of the broadly defined Saxifragaceae. Molecular phylogenetic data (Soltis et al. 2001) show that the narrowly defined Saxifragaceae fall into two major groups: Saxifraga, and the heucheroid clade encompassing all other genera. Molecular data further show that Saxifraga, as traditionally understood, is polyphyletic, comprising two distinct lineages (treated here as Saxifraga and Micranthes) and the monospecific North American Cascadia. The major split between Saxifraga and the heucheroid clade is supported not only by molecular data from six DNA regions but by differences in patterns of floral morphology. Saxifraga has a relatively uniform floral morphology (radially symmetric flowers, with bilateral symmetry restricted to one Asian group of species, which consistently have the same number of sepals, petals, stamens, and carpels). Almost all of the variation in the family in numbers of sepals, petals, stamens, and carpels occurs in the heucheroid clade. Radially symmetric flowers predominate there, but some bilateral flowers are found in Bensoniella, Micranthes, Tolmiea, and some species of Heuchera."

NOTE: Past and contemporary research have indicated that Mitella is a polyphyletic group best treated as multiple genera. The treatment here reflects that view, which is also consistent with how these taxa were treated by Abrams in "Illustrated Flora of the Pacific States".

FNA8: "Mitella is treated here in the broad sense; phylogenetic data indicate that it is polyphyletic (D. E. Soltis et al. 1990; Soltis and R. K. Kuzoff 1995). Historically, four or five genera have been recognized (including Mitella, Ozomelis Rafinesque, Pectiantia Rafinesque). Formal restructuring of generic boundaries is complicated by the presence of nearly a dozen Asian species (M. Wakabayashi 2001) and lack of a comprehensive understanding of the genus relative to the rest of Saxifragaceae. Mitella nuda and M. diphylla, both with ten stamens, form a clade that would comprise a narrowly defined Mitella. A second clade composed of M. diversifolia, M. stauropetala, M. trifida, and Conimitella williamsii would form a second, distinct genus. Molecular data suggest that M. breweri, M. caulescens, and M. pentandra also form a distinct clade and perhaps a third, distinct genus. The relationships of M. ovalis are less certain; some analyses suggest that it may be sister to the genus Tolmiea (Soltis and Kuzoff; Kuzoff and Soltis, unpubl.)."

Family Synonyms: (none)

Literature: (none)

Family treatment authored by Fred Weinmann; last updated 10/21/2017 by David Giblin
Taxon (native species in boldface) # Synonyms Common Names
Bolandra oregana S. Wats.   [FNA8, H&C] 1 northern false coolwort
Boykinia intermedia (Piper) G.N. Jones   [FNA8] 3
Boykinia occidentalis Torr. & Gray   [FNA8] 4 coastal brookfoam
Cascadia nuttallii (Small) A. M. Johnson   [FNA8] 1 Nuttall's saxifrage
Chrysosplenium glechomifolium Nutt.   [FNA8, H&C] 2 Pacific golden-saxifrage, Pacific watercarpet
Chrysosplenium tetrandrum (Lund ex Malmgr.) Th. Fries   [FNA8, H&C] 2 northern golden-saxifrage
Elmera racemosa (S. Watson) Rydberg   [FNA8] 3 Elmera
Hemieva ranunculifolia (Hook.) Raf.   [JPM2] 3
Heuchera chlorantha Piper   [FNA8, H&C] 0 meadow alumroot, green-flowered alumroot, tall alumroot
Heuchera cylindrica Dougl.   [FNA8] 13 poker alum-root
Heuchera glabra Willd. ex Roemer & J.A. Schultes   [FNA8, H&C] 0 smooth alumroot, alpine alumroot
Heuchera grossulariifolia Rydb.   [FNA8] 3 gooseberry-leaved alumroot
Heuchera micrantha Dougl. ex Lindl. var. diversifolia (Rydb.) Rosendahl, Butters & Lakela   [FNA8, H&C] 2 small-flowered alumroot
Heuchera micrantha Douglas ex Lindley var. hartwegii (S. Watson ex Wheelock) Rosendahl   [FNA8] 2
Heuchera micrantha Dougl. ex Lindl. var. micrantha    [FNA8, H&C] 0 small-flowered alumroot
Leptarrhena pyrolifolia (D. Don) R. Br. ex Ser.   [FNA8, H&C] 6 leatherleaf saxifrage, pearleaf
Lithophragma glabrum Nutt.   [FNA8] 6 bulbiferous prairie star, bulbous woodlandstar
Lithophragma parviflorum (Hook.) Nutt   [FNA8] 2 small-flowered prairie star
Lithophragma tenellum Nutt.   [FNA8] 6 slender woodlandstar
Micranthes apetala (Piper) Small   [FNA8] 3 Tiny swamp saxifrage
Micranthes ferruginea (Graham) Brouillet & Gornall   [FNA8] 6 rusty saxifrage
Micranthes fragosa (Suksdorf ex Small) Small    [FNA8] 5
Micranthes gormanii (Suksdorf) Brouillet & Gornall   [FNA8] 2 Gorman's saxifrage
Micranthes idahoensis (Piper) Brouillet & Gornall    [FNA8] 4 Idaho saxifrage
Micranthes integrifolia (Hook.) Small   [FNA8] 3 Whole-leaf saxifrage
Micranthes lyallii (Engl.) Small   [FNA8] 5 Lyall’s or red-stemmed saxifrage
Micranthes nelsoniana (D. Don) Small var. cascadensis (Calder & Savile) Gornall & H. Ohba   [FNA8] 3 dotted or Nelson’s saxifrage
Micranthes nidifica (Greene) Small   [FNA8] 7 swamp saxifrage
Micranthes occidentalis (S. Wats.) Small   [FNA8] 6 western or redwool saxifrage
Micranthes odontoloma (Piper) W.A. Weber   [FNA8] 5
Micranthes oregana (Howell) Small   [FNA8] 7 Oregon or bog saxifrage
Micranthes rufidula Small   [FNA8] 7
Micranthes tischii (Skelly) Brouillet & Gornall   [FNA8] 1 Olympic saxifrage
Micranthes tolmiei (Torrey & A. Gray) Brouillet & Gornall   [FNA8] 3 Tolmie's or alpine saxifrage
Mitella nuda L.   [FNA8, H&C] 1 bare-stemmed mitrewort
Mitellastra caulescens (Nutt.) T.J. Howell   [JPM2] 1 leafy mitrewort, star-shaped mitrewort
Ozomelis diversifolia (Greene) Rydb.   [JPM2] 1 angle-leaf bishop's-cap
Ozomelis stauropetala (Piper) Rydb.   [JPM2] 2 side-flowered mitrewort, cross-shaped mitrewort
Ozomelis trifida (Graham) Rydberg   [JPM2] 6 three-toothed mitrewort
Pectiantia breweri (Gray) Rydb.   [JPM2] 1 Brewer's mitrewort,feathery bishop's-cap
Pectiantia ovalis (Greene) Rydb.   [JPM2] 1 coastal mitrewort, coastal bishop's cap
Pectiantia pentandra (Hook.) Rydb.   [JPM2] 1 alpine mitrewort, five-stamen bishop's-cap
Saxifraga adscendens L.   [FNA8] 3 wedge-leaf saxifrage
Saxifraga bronchialis L. ssp. austromontana (Wieg.) Piper   [FNA8] 3 spotted saxifrage, matted saxifrage
Saxifraga cernua L.   [FNA8, H&C] 2 nodding saxifrage
Saxifraga cespitosa L.   [FNA8] 7 tufted or tufted alpine saxifrage
Saxifraga hyperborea R. Brown   [FNA8] 6 pygmy saxifrage
Saxifraga mertensiana Bong.   [FNA8, H&C] 1 woodland saxifrage, Merten's saxifrage
Saxifraga oppositifolia L. ssp. oppositifolia    [FNA8] 2 purple mountain saxifrage, purple saxifrage, twinflowered saxifrage
Saxifraga tridactylites L.   [Draft Revised H&C; FNA8] 0 rue-leaved saxifrage
Saxifraga vespertina (Small) Fedde   [FNA8] 4
Saxifragopsis fragarioides (Greene) Small   [FNA8] 1 strawberry saxifrage
Suksdorfia violacea Gray   [FNA8, H&C] 0 violet mock brookfoam
Sullivantia oregana S. Wats.   [FNA8, H&C] 0 Oregon coolwort
Tellima grandiflora (Pursh) Dougl. ex Lindl.   [FNA8, H&C] 2 fringecup, fragrant fringecup
Tiarella trifoliata L. var. laciniata (Hook.) Wheelock   [FNA8, H&C] 2 cut-leaved foamflower
Tiarella trifoliata L. var. trifoliata    [FNA8, H&C] 0 three-leaf foamflower
Tiarella trifoliata L. var. unifoliata (Hook.) Kurtz   [FNA8, H&C] 2 simple-leaved foamflower
Tolmiea menziesii (Pursh) Torr. & Gray   [FNA8, H&C] 1 piggyback-plant

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