BORAGINACEAE. 207 



deeply 5-cleft or parted; corolla tubular-funnelform or trumpet- 

 shaped to almost campanulate, the open throat bearing obvious 

 or obsolete transverse folds or crests; filaments flattened or 

 nearly filiform; style filiform; stigma entire; nutlets from some- 

 what fleshy to membranaceous, not armed with barbed prickles. 



Plants tall and leafy, 50-100 cm. high, the leaves thin and 

 broad. 

 Upper leaf surface smooth or merely papillose. M. subcordala. 



Upper leaf surface strigose. 



Calyx lobes canescent. M. membranacea. 



Calyx lobes not canescent. M. paniculala. 



Plants low, 15-40 cm. high, the leaves narrow or thickish. 



Leaves glabrous or merely papillose above. M. pulchella. 



Leaves strigose above. 



Corolla tube 3 or 4 times as long as the limb. M. oblongifolia. 



Corolla tube once or twice as long as the limb. M. horneri. 



Mertensia subcordata Greene. Very similar to M. membranacea and 

 M. paniculata. Leaves glabrous or merely papillose above; calyx-lobes pu- 

 bescent on the back. In the Blue Mountains. 



Mertensia membranacea Rydb. Tall, erect, 60-120 cm. high, branched 

 above; leaves ovate to ovate-lanceolate, acuminate, rounded or cuneate at 

 base, appressed strigose above, sparsely pilose beneath, 3-10 cm. long, the 

 lower with petioles as long as the blades; racemes few-flowered, loosely panicled; 

 calyx canescent, the lobes lanceolate, acute; corolla blue, 8-14 mm. long, its 

 tube twice as long as the calyx, and little longer than the limb. In mountain 

 woods, Mount Carlton; and the Thatuna Hills, Idaho. 



Mertensia paniculata (Ait.) G. Don. Very similar to M. membranacea but 

 the calyx green, the lobes glabrous except on the margins. Mount Carlton, 

 Kreager: and Cedar Mountain, Idaho. 



Mertensia pulchella Piper. Stems erect, solitary, or rarely two, glabrous, 

 15-20 cm. high; tubers shallow-seated, simple or fasciculate-branched, black; 

 leaves green, elliptic or ovate, mostly obtuse, thickish, glabrous beneath, 

 more or less papillose above, scabrous-ciliate, the lower narrowed at base and 

 short-petioled, the middle and upper ones ovate, sessile, often half-clasping, 

 2-10 cm. long; lowest leaves much reduced, scarious; flowers in a close cluster, 

 usually 10-15; calyx parted nearly to the base, the lobes oblong-lanceolate, 

 very acute denticulate; corolla blue, its tube three to four times as long as the 

 calyx and nearly as broad as the ampliate limb; filaments dilated, as long as 

 the anthers; nutlets small, dark gray, finely muriculate, attached by a pale 

 and prominent scar, inclosed in the tube of the much enlarged fruiting calyx. 

 Along the Clearwater River and in the Craig Mountains, Idaho. 



Mertensia oblongifolia (Nutt.) G. Don. Very similar to M. pulchella but 

 the leaves appressed strigose above; corolla tube three or four times as long 

 as the limb. On moist hillsides, not rare. 



Mertensia horneri Piper. Stems 8-15 cm. high, glabrous, solitary or 

 rarely 2 or 3, erect from a shallow-seated oblong black tuber; basal leaves 

 none; cauline 2-5, oblong, obtuse, pale and somewhat glaucous, appressed- 

 puberulent above, glabrous beneath, sessile or the lower ones short-petioled, 

 2-3 cm. long; lowest leaves reduced and scarious; inflorescence close; calyx 

 glaucous, parted nearly to the base, its lobes oblong-lanceolate, very acute, 

 denticulate-ciliate on the margin; corolla blue, 10-12 mm. long, its tube about 

 twice as long as the calyx; filaments dilated, as long as the anthers. Waits- 

 burg, Horner. 



