SAXIFRAGE FAMILY 371 



12. TIARELLA L. Sp. PI. 405. 1753. 



Perennial slender erect herbs with the leaves mainly basal, long-petioled, lobed or 

 3-foliate, with small stipules adnate to the petiole and lateral leafy flowering shoots from 

 a scaly rootstock. Inflorescence a raceme or, in ours, a panicle. Hypanthium small, short- 

 campanulate, nearly free from the ovary. Sepals 5, ovate or lanceolate. Petals 5, clawed, 

 with oblong or elliptic blades or, as in ours, clawless and linear-subulate. Stamens 10, 

 conspicuously exserted, with long filiform filaments. Ovary 1-celled, 2-horned, with 

 2 parietal, in fruit nearly basal placentae. Styles 2, elongated. Capsule membranous, 

 with 2 very unequal valves. Seeds usually few. [Name a diminutive of the Greek tiara, 

 a high cap, in allusion to the form of the capsule.] 



A genus of about 6 species, natives of North America, Japan and the Himalayas. Besides the following, two 

 species occur in the eastern United States. Type species, Tiarella cordifolia L. 



Leaves ternately compound. 



Leaflets coarsely crenate-dentate. 1. T. trifoliata. 



Leaflets deeply laciniate. 2. T. laciniata. 



Leaves simple, merely lobed. 3. T. unifoliata. 



1. Tiarella trifoliata L. Laceflower. Fig. 2276. 



Tiarella trifoliata L. Sp. PI. 406. 1753. 



Tiarella stenopetala Presl, Rel. Haenk. 2: 55. 1831. 



Blondia trifoliata Raf. Fl. Tell. 2: 75. 1836. 



Tiarella rhombifolia Nutt. in Torr. & Gray, Fl. N. Amer. 1: 588. 1840. 



Sparsely and softly hirsute acaulescent perennial ; flowering branches slender, 2-6 dm. high, 

 glabrous or glabrate below, glandular-hirsute above, 2-4-leaved. Leaves trifoliate, the petiolules 

 very short; petioles of the basal ones 5-15 cm. long, glabrous to conspicuously villous-hirsute ; 

 middle leaflet rhombic, more or less 3-lobed and repandly apiculate-dentate with broadly ovate 

 teeth, sparingly hirsute, becoming glabrous in age, 2-8 cm. long ; lateral leaflets obliquely ovate, 

 mostly 2-cleft ; leaves of the flowering branches similar but smaller ; inflorescence an elongated 

 and narrow panicle; sepals white or pinkish, narrowly ovate, acute, glandular-dotted on the 

 back, about 1 . 5 mm. long ; petals white, linear-subulate, like the stamens 3-4 times as long as the 

 sepals ; carpels narrowly oval, obtusish, the larger 7-10 mm., the smaller 4-6 mm. long. 



In forests, Humid Transition Zone; coastal region of central Oregon north to Alaska and southeast into 

 eastern Asia. Type locality: "Habitat in Asia boreali." April-Aug. 



2. Tiarella laciniata Hook. Laciniate Tiarella. Fig. 2277. 



Tiarella laciniata Hook. Fl. Bor. Amer. 1: 239. 1832. 



Petalosteira laciniata Raf. Fl. Tell. 2: 74. 1836. 



Tiarella trifoliata var. laciniata Wheelock, Bull. Torrey Club 23: 72. 1896. 



Flowering branches 2.5-4 dm. high, glabrous to sparingly glandular-hirsute, especially 

 above; leaves trifoliate, sparingly hirsute; middle leaflet rhombic in outline, deeply 2-cleft and 

 with oblong or ovate mucronate teeth, 2-6 cm. long ; lateral ones obliquely ovate, laciniately and 

 unequally 2-cleft, almost to the base on the outside, and farther up on the leaflet and not so 

 deeply on the inside, otherwise cleft and toothed as the middle one; leaves of the flowering 

 branches similar but smaller and the upper short-petioled ; inflorescence, flowers and fruit as in 

 the preceding. 



In woods, rare, Humid Transition and Canadian Zones; southern Alaska to northern Oregon. Type locality 

 North-West coast of America," Menzies. June-Aug. 



3. Tiarella unifoliata Hook. Sugar-scoop. Fig. 2278. 



Tiarella unifoliata Hook. Fl. Bor. Amer. 1 : 238. 1832. 

 Petalosteira unifoliata Raf. Fl. Tell. 2: 74. 1836. 

 Heuchera calif ornica Kell. Proc. Calif. Acad. 5: 53. 1873. 

 Tiarella unifoliata var. procera A. Gray, Bot. Calif. 1: 199. 1876. 

 Tiarella trifoliata var. unifoliata Kurtz, Bot. Jahrb. 19: 378. 1894. 

 Tiarella calif ornica Rydb. N. Amer. Fl. 22: 118. 1905. 



_ Flowering branches 1-5 dm. high, glabrous or slightly to densely hirsute with whitish hairs, 

 viscid-puberulent to glandular-pubescent above. Basal leaves broadly cordate in outline spar- 

 ingly or quite hirsute on both sides to glabrate in age, 4-10 cm. wide, acutely 3-5-lobed with very 

 deep to mostly shallow, broadly ovate, acute or obtusish lobes, doubly crenate to coarsely crenate- 

 dentate, the teeth mucronate; petioles 0.5-2 dm. high, glabrous to densely hirsute with whitish 

 hairs ; cauhne leaves 1-4, similar to the basal but smaller and shorter-petioled ; inflorescence a 

 narrow panicle; sepals white to pinkish, ovate-oblong, the upper somewhat larger and longer 

 than the lower, 1.5-2.5 mm. long; the linear-subulate white petals and the stamens 2-3 times as 

 long; carpels oblong, abruptly acute, the larger 9-12 mm. long, the smaller 4-6 mm. long. 



Shaded ravines and woods, Humid Transition and Canadian Zones; Alberta and southern Alaska to western 

 Montana and south through Washington and Oregon and the coastal region of California to the Santa Cruz 

 Mountains. Type locality: Rocky Mountains, near the source of the Columbia River. May-July. Forms in which 

 the leaves approach those of Tiarella trifoliata are not infrequent. 



13. TOLMIEA Torr. & Gray, Fl. N. Amer. 1 : 582. 1840. 

 Glandular-pubescent perennial herbs with scaly rootstocks, long-petioled cordate 



