Herbs, rhizomatous, not stoloniferous; caudex sometimes bearing bulbils. Flowering stems erect, leafy, 8–85 cm, stipitate-glandular. Leaves in basal rosette and cauline; cauline leaves (1–)2(–10), usually alternate (opposite in L. cymbalaria), unlobed, lobed, or palmately compound, sometimes with bulbils in axils; stipules present; petiole stipitate-glandular; blade rhombic or orbiculate to reniform, lobed, base cordate, hastate, rounded, ligulate, or cuneate, ultimate margins entire or toothed, apex obtuse or acute, surfaces often stipitate-glandular; venation palmate. Inflorescences compact or lax racemes, arising from axillary buds in basal rosette, 2–12(–25)-flowered, sometimes flowers solitary, (flowers sometimes replaced by bulbils), bracteate. Flowers: hypanthium partially adnate to proximal 1/2 to entire length of ovary, free from ovary 1–2 mm, green; sepals 5, green tinged with red; petals 5, white or pink; nectariferous tissue inconspicuous; stamens 10, (inserted on hypanthium, inner whorl attached proximal to point of petal insertion); filaments filiform; (anthers cordate); pistil 3-carpellate; ovary superior to 1/2 or almost completely inferior, 1-locular, carpels fully connate at ovaries; placentation parietal; styles 3; stigmas 3. Capsules 3-beaked. Seeds (50–200), usually dark brown, ovoid, smooth, wrinkled, or tuberculate. x = 7.
w North America.
Tellima R. Brown [unranked] Lithophragma Nuttall, J. Acad. Nat. Sci. Philadelphia 7: 26. 1834 (as Lithofragma); Pleurendotria Rafinesque, name rejected
Species 10 (10 in the flora).
Kuzoff, R. K., D. E. Soltis, L. Hufford, and P. S. Soltis. 1999. Phylogenetic relationships within Lithophragma (Saxifragaceae): Hybridization, allopolyploidy, and ovary diversification. Syst. Bot. 24: 598–615.
Kuzoff, R. K., L. Hufford, and D. E. Soltis. 2001. Structural homology and developmental transformations associated with ovary diversification in Lithophragma (Saxifragaceae). Amer. J. Bot. 88: 196–205.
|1||Leaves palmately compound, 3-foliolate; seeds spiny.||Lithophragma maximum|
|1||Leaves unlobed or lobed, or 3-foliolate; seeds smooth, wrinkled, tuberculate, or rough||> 2|
|2||Stigma papillae in narrow subapical band; seeds smooth or wrinkled||> 3|
|2||Stigma papillae covering apical surface; seeds tuberculate, tubercles in 3-19 rows, blunt or spinelike||> 6|
|3||Leaf blades light green; cauline leaves 3-lobed, appearing pinnatifid; flowers persistent, slightly pendulous; racemes erect; petals 5-7-lobed; ovaries to 1/2 inferior.||Lithophragma tenellum|
|3||Leaf blades dark green or reddish green; cauline leaves 3-foliolate or 3-lobed; flowers deciduous if unfertilized, horizontal; racemes often lax, nodding; petals 3-lobed; ovaries 1/2+ inferior||> 4|
|4||Hypanthia elongate-obconic, length 3-4 times diam.; petals pink; flowers fragrant.||Lithophragma trifoliatum|
|4||Hypanthia obconic to obconic-elongate, length 2 times diam.; petals usually white, sometimes pink; flowers not fragrant||> 5|
|5||Cauline leaves 3-foliolate; hypanthia obconic-elongate; petals white or pink, often with prominent venation, 3-lobed, obovate-rhombic, widely spreading, ultimate margins entire; ovaries 1/2+ inferior.||Lithophragma parviflorum|
|5||Cauline leaves 3-lobed; hypanthia obconic; petals white with obscure venation, usually shallowly 3-lobed, ovate-elliptic, not widely spreading, ultimate margins sometimes with extra tooth, (lobes acute); ovaries ± completely inferior.||Lithophragma affine|
|6||Cauline leaves opposite (1 pair); flowering stems simple; petals unlobed, without serrations at base, ultimate margins entire.||Lithophragma cymbalaria|
|6||Cauline leaves alternate; flowering stems often branched; petals lobed or, if unlobed, margins sometimes with serrations at base||> 7|
|7||Hypanthia broadly campanulate; flowers pendulous, petals partly included, ovate-elliptic, ultimate margins lacerate; flowers ± sessile.||Lithophragma campanulatum|
|7||Hypanthia narrowly campanulate; flowers horizontal, petals completely exserted, obovate-pandurate, ovate-elliptic, or ovate and palmately 5-lobed, ultimate margins entire; flowers long-pedicellate||> 8|
|8||Hypanthia with truncate base; petals white, simple or 3-7-lobed; flowers not fragrant; racemes lax, nodding; cauline leaves 2-10; ovaries superior.||Lithophragma heterophyllum|
|8||Hypanthia with acute, obtuse, or hemispheric base; petals white or pink, unlobed, serrately 3-5-lobed, or 5-lobed; flowers sometimes fragrant; racemes erect; cauline leaves 2-4; ovaries to 1/2 inferior||> 9|
|9||Plants usually robust; leaves usually unlobed or 3-5-lobed; petals white, unlobed or 3-5-lobed with serrations at base; inflorescences 2(-3)-branched, 3-5(-25)-flowered racemes, flowers rarely replaced with bulbils.||Lithophragma bolanderi|
|9||Plants usually fragile; leaves lobed (lobes rounded); petals usually pink, rarely white, palmately 5-lobed, base without serrations; inflorescences rarely branched (unless plant with bulbils), solitary flowers or 2-5(-7)-flowered racemes, often appearing corymbose; flowers sometimes replaced with bulbils.||Lithophragma glabrum|