Penstemon sect. Chamaeleon

Crosswhite

Sida 2: 339. 1966.

Treatment appears in FNA Volume 17. Treatment on page 108. Mentioned on page 93.

Herbs. Stems retrorsely hairy or puberulent, sometimes glandular-pubescent distally or glabrescent, not glaucous. Leaves basal and cauline, basal usually absent at anthesis, opposite, leathery or not, glabrous, puberulent, or retrorsely hairy, not glaucous; basal and proximal cauline petiolate, sometimes short-petiolate or sessile (P. dasyphyllus); cauline sessile, sometimes short-petiolate (P. lanceolatus), blade lanceolate or linear, margins entire. Thyrses interrupted, ± secund to cylindric, axis glandular-pubescent or glabrous, cymes 1 or 2 per node; peduncles and pedicels ascending to erect. Flowers: calyx lobes: margins entire or erose (P. stenophyllus), herbaceous or narrowly scarious, sometimes broadly scarious (P. stenophyllus), glandular-pubescent or glabrous; corolla lavender to blue, violet, purple, red, or scarlet, bilaterally symmetric, bilabiate, not personate, ventricose or tubular-funnelform, glandular-pubescent externally, glabrous or glandular-pubescent internally abaxially, throat abruptly or gradually inflated, not constricted at orifice, rounded to 2-ridged abaxially; stamens included to exserted, filaments glabrous, pollen-sacs parallel to divergent, navicular to slightly saccate, dehiscing completely or incompletely, distal 1/5 or less sometimes indehiscent, connective splitting, sides glabrous, sutures denticulate, teeth to 0.2–0.3 mm; staminode included or exserted, flattened distally, 0.3–2.6 mm diam., tip recurved, glabrous; style glabrous. Capsules glabrous. Seeds brown to dark-brown, angled, 1.9–3.2 mm.

Distribution

sw United States, Mexico

Discussion

Species 4 (3 in the flora).

Crosswhite circumscribed sect. Chamaeleon to include a group of southern species distinguished by incompletely dehiscent pollen sacs with prominently denticulate sutures. Penstemon punctatus Brandegee, a species not treated by Crosswhite, might belong here; the only specimens of that species seen were from Coahuila, Mexico.

Key

1 Corollas scarlet to red, tubular-funnelform, glandular-pubescent internally abaxially. Penstemon lanceolatus
1 Corollas violet to blue, lavender, or purple, ventricose, glabrous internally. > 2
2 Thyrse axes glandular-pubescent. Penstemon dasyphyllus
2 Thyrse axes glabrous. Penstemon stenophyllus

"/4+timescorollathroat" is not declared as a valid unit of measurement for this property.

Craig C. Freeman +
Crosswhite +
glabrous +  and glandular-pubescent +
alternate +, opposite +, whorled +, helical +  and subopposite +
sessile +, short-petiolate +  and petiolate +
cauline +, proximal +  and basal +
not glaucous +, hairy +, puberulent +  and glabrous +
not +  and leathery +
linear;lanceolate +
not +  and leathery +
short-tubular +  and short-campanulate +
not personate +  and bilabiate +
lavender +  and blue violet purple red or scarlet +
glandular-pubescent +  and glabrous +
tubular-funnelform +  and ventricose +
ventricose-ampliate +  and ampliate +
2 +  and 1 +
scale-like +  and not needlelike +
sw United States +  and Mexico +
drupe-like +
curved +  and straight +
1 +  and 4 +
membranous +
terminal +  and axillary +
persistent +  and deciduous +
cauline +  and basal +
orbiculate;linear;orbiculate;linear;truncate;oblanceolate;obovate;oblong;elliptic;round;lanceolate;ovate +
erose +  and entire +
glabrous +  and glandular-pubescent +
toothed +  and entire +
scarious +  and herbaceous +
axile +  and parietal +
basal +, apical +  and superior +
tenuinucellate +, unitegmic +  and hemitropous +
campylotropous +, hemianatropous +  and anatropous +
ascending +  and erect +
ascending;erect +
5 +  and 4 +
parallel +  and divergent +
navicular-sigmoid +
indehiscent +  and dehiscing +
navicular +  and slightly saccate +
crosswhite1966a +
minute +
brown +  and dark-brown +
0.19 cm1.9 mm <br />0.0019 m <br /> - 0.32 cm3.2 mm <br />0.0032 m <br /> +
included +  and exserted +
0.03 cm0.3 mm <br />3.0e-4 m <br /> - 0.26 cm2.6 mm <br />0.0026 m <br /> +
exserted +  and included +
subalternate +, alternate +, whorled +  and opposite +
climbing +  and scrambling +
sprawling +, creeping +  and prostrate +
decumbent;ascending;decumbent;ascending;erect;prostrate +
not glaucous +, glabrescent +, glandular-pubescent +, puberulent +  and hairy +
papillate +
denticulate +
Penstemon sect. Chamaeleon +
Penstemon subg. Penstemon +
section +
rounded +  and 2-ridged +
not constricted +
secund +  and interrupted +
cylindric +
0.02 cm0.2 mm <br />2.0e-4 m <br /> - 0.03 cm0.3 mm <br />3.0e-4 m <br /> +
gibbous +  and not spurred +
short-petiolate +  and sessile +