Miiella. SAXIFRAGACE^E. 199 



Exp. 95. Lithophragma tenella & L. glabra (a smoother form), N"utt. in Ton. 

 & Gray, Fl. i. 584 ; Gray, 1. c. 



Rocky moist ground, through the northern portion of the Sierra Nevada ; thence to the Rocky 

 Mountains. Calyx 1 or 2 lines long. Petals 2 or 3 lines long, generally pink or rose-color. 

 Granulate bulblets copious at the root, and sometimes in the place of flowers in the raceme. 



6. TIARELLA, Linn. 



Calyx 5-parted ; the base almost free from the ovary, the lobes more or less 

 colored. Petals 5, undivided, small, with short claws. Stamens 10 : filaments long 

 and slender : anthers with 2 parallel cells. Ovary 1-celled, compressed, 2-horned 

 (the horns or lobes tapering into long filiform styles), soon unequal and dehiscent, 

 one valve or carpel in fruit lanceolate-elongated, the other remaining very much 

 shorter. Seeds rather few and only at the base of each parietal placenta, globular, 

 with a smooth and shining crustaceous coat. Perennial low or slender herbs, often 

 multiplying by summer runners ; with palmately lobed or divided alternate leaves, 

 and sometimes scaly stipules at the base of the petiole, and a terminal raceme or 

 panicle of small white flowers. 



A North American and North Asiatic genus of five species, one inhabiting the Atlantic States 

 and two the Pacific coast. 



1. T. unifoliata, Hook. Somewhat pubescent or hairy: flowering stems a span 

 to a foot or more long : leaves thin, cordate, either rounded or somewhat triangular, 

 3 - 5-lobed and the lobes crenate-toothed ; the radical ones slender-petioled ; the 

 cauline mostly one, smaller, and short-petioled, or sometimes (mainly on decumbent 

 and later flowering shoots) 2 or 3 similar to the radical: panicle raceme-like and 

 loose: petals small and inconspicuous, almost filiform. Fl. i. 238, t. 81. Heuchera 

 longipetala, Mocino, Ic. Ined. t. 423. 



Shaded ravines and woods, San Mateo Co. (Kellogg), Mendocino Co. (Bolander), and north 

 through British Columbia. The Californian and some of the more northern specimens incline to 

 have elongated and 2-3-leaved flowering stems, and whole plant more hairy, the var. procera: 

 but this is merely a luxuriant state. The lobing of the leaves varies, so that it may pass into 



T. TRIFOLIATA, Linn. ( T. stenopetala, Presl), which extends from the mountains of Oregon to 

 Alaska and N. W. Asia, has most of its leaves divided into three distinct leaflets. 



7. MITELLA, Tourn. MITRE-WORT. 



Calyx short ; the broad tube coherent with the base of the ovary and dilated 

 beyond it, 5-lobed ; the lobes valvate in the bud, spreading. Petals 5, inserted on 

 the throat of the calyx, very slender, pinnately parted or 3-cleft ; the divisions 

 almost capillary. Stamens 10 or 5, very short : anthers cordate or reniform, 2- 

 celled. Ovary short and broad, 1-celled, with 2 parietal or almost basal placentae, 

 mainly or partly superior : styles 2, very short : stigmas capitellate. Capsule glob- 

 ular or depressed, hardly at all lobed, opening across the broad summit. Seeds 

 several to each placenta, obovate, with a firm and smooth black and shining close 

 crustaceous coat. Small perennials (N. American and N. E. Asian) ; with more or 

 less creeping slender rootstocks and summer runners, small and greenish or some- 

 times white flowers in a simple raceme, and cordate or round-reniform simple leaves, 

 which are all radical and long-petioled, or two or more on flowering stems, these in 

 one species (of E. North America) opposite. Petioles, &c., mostly loosely hirsute. 



1. M. Breweri, Gray. Leaves all in a cluster on the rootstock, round-reniform, 

 crenate and crenately incised, of comparatively firm texture, soon nearly glabrous, 



