818 MISC. PUBLICATION 4 2 3, U. S. DEPT, OF AGRICULTURE 

 9. MIMULUS. 42 Monkeyflower 



Plants herbaceous, annual or perennial ; stems leafy or scapose ; leaves 

 opposite or basal, sessile or petioled, the blades entire or dentate; 

 flowers in leafy terminal racemes, or axillary and solitary, often showy; 

 calyx tubular or campanulate, 5-angled, sometimes bilabiate; corolla 

 bilabiate or nearly regular, with a pair of longitudinal ridges on the 

 lower side of the throat; stigma 2-lobed, the lobes separate or united; 

 capsule usually longitudinally dehiscent (2-valved) ; seeds numerous. 



Many of the species have showy, handsome flowers, and some of 

 them are in cultivation. Most of the Arizona species grow in wet soil. 



Key to the species 



1. Corolla normally scarlet or carmine, 3 to 5.5 cm. long, bilabiate, the upper lip 

 erect; plants perennial, with creeping rootstocks, loosely villous and some- 

 what viscid with flaccid hairs; leaf blades sessile with a somewhat clasping 

 base, sharply dentate or serrate; pedicels nearly as long as to much longer 

 than the subtending leaves; calyx tubular-obconic, the teeth nearly equal; 

 stamens exserted (2) . 

 2. Plant stoloniferous; stems not more than 20 cm. long, procumbent or pros- 

 trate; leaf blades commonly obovate; corolla tube moderately to greatly 

 surpassing the calyx 1. M. eastwoodiae. 



2. Plant not stoloniferous; stems usually at least 30 cm. long, erect or ascend- 



ing; leaf blades commonly oblong, oblong-ovate, or rhombic-elliptic. 



2. M. CARDINALIS. 



1. Corolla not scarlet or carmine, less than 3 cm. long or, if longer, then bright 

 yellow and usually spotted with red (3). 



3. Pedicels not more than one-third as long as the calyx; plants annual; stems 



not more than 25 cm. long, erect or ascending, usually branching from 



the base; leaf blades entire or nearly so; corolla 15 to 25 mm. long, with 



a narrow tube and throat and a spreading limb; stamens included; 



plants of dry, gravelly slopes (4) . 



4. Corolla distinctly bilabiate, yellow, sometimes tinged or spotted with 



reddish purple; plant glandular-puberulent; leaf blades lanceolate, 



oblanceolate, or narrowly elliptic; anthers glabrous^_ 3. M. parryi. 



4. Corolla nearly regular, mallow pink, with a yellow tube and usually a 



bright yellow patch in the throat; plant villous, usually viscid; leaf 

 blades lanceolate to broadly ovate or obovate; anthers usually his- 



pidulous 4. M. BIGELOVII. 



3. Pedicels nearly as long as, to much longer than, the calyx; plants of moist 

 soil (5). 



5. Fruiting calyx strongly asymmetric, the upper tooth much longer than 



the others; corolla distinctly bilabiate, yellow, the throat often spotted 

 with red (6). 

 6. Fruiting calyx open; plants perennial; stems glabrous or very nearly so, 

 strongly decumbent to creeping and rooting at the nodes; corolla 

 7 to 15 mm. long (7). 

 7. Stems slender, less than 10 cm. long, closely matted; leaf blades pilose 

 with white, subappressed hairs, less than 10 mm. long, flabelli- 

 form or suborbicular, ^usually shallowly crenate or dentate; 

 corolla lobes denticulate' or somewhat laciniate. 



5. M. DENTILOBUS. 



7. Stems relatively stout, commonly more than 10 cm. long, not matted 

 or very loosely so; leaf blades glabrous or sparsely pilose, 10 to 



40 mm. long; corolla lobes mostly entire 6. M. glabratus. 



6. Fruiting calyx more or less closed by the connivent teeth; stems usually 

 erect or ascending; stems and leaves more or less pubescent in the 

 inflorescence, commonly glabrous or glabrate below; leaf blades 

 mostly denticulate to sharply and coarsely dentate (8). 



« Ke/erence: Grant, Adele L. a monograph of the genus mimulus. Mo. Bot. Gard. Ann. 11: 

 99-388. 1924. 



