The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

abajo beardtongue, handsome beardtongue, handsome penstemon

bush penstemon, gilia beardtongue, pink plains penstemon

Stems

ascending to erect, 14–40(–60) cm, glabrous.

(20–)30–40(–60) cm, glabrous or scabrous proximally.

Leaves

basal and cauline, glabrous;

basal and proximal cauline 40–65(–110) × 8–20(–30) mm, blade obovate, base tapered, apex obtuse to acute, sometimes mucronate;

cauline 2–4 pairs, sessile, (9–)12–60 × 7–26 mm, blade lanceolate to ovate or elliptic, base tapered to clasping or cordate-clasping, apex obtuse to acute, sometimes mucronate.

(7–)10–25 pairs, (3–)5–30(–40) × 0.5–1(–2.5) mm, blade base tapered, margins glabrous or scabrous, apex acuminate to mucronate.

Thyrses

interrupted or ± continuous, secund, sometimes cylindric, 5–23 cm, axis glabrous, verticillasters 4–8, cymes 1–3(or 4)-flowered;

proximal bracts ovate to lanceolate, (3–)7–38 × (1–)2–18 mm;

peduncles and pedicels glabrous, peduncles to 28 mm.

6–15 cm, verticillasters 6–10, cymes 1–3-flowered;

proximal bracts linear, 6–27(–33) × 0.3–1.5 mm;

peduncles and pedicels glabrous or scabrous.

Flowers

calyx lobes ovate to lanceolate, 5–6.7(–7.2) × 2–3(–3.7) mm, margins entire or erose, broadly scarious, glabrous;

corolla lavender to violet, blue, pinkish blue, or white, with or without reddish violet nectar guides, tubular-funnelform, 17–20(–22) mm, glabrous externally, sparsely white-villous internally abaxially or glabrous, tube 5–8 mm, throat gradually inflated, 5–6 mm diam., rounded abaxially;

stamens included or longer pair reaching orifice, pollen sacs opposite, 1.1–1.6 mm, sutures papillate;

staminode 8–9 mm, reaching orifice or slightly exserted, 0.6–1 mm diam., tip strongly recurved, distal 3–4 mm sparsely to densely villous, hairs mostly along margins, yellowish, to 1 mm;

style 10–12 mm.

calyx lobes ovate, 1.5–3.5 × 1–1.5 mm;

corolla pink (limb milky pink or milky white), lined internally abaxially with reddish purple nectar guides, salverform, (14–)16–22(–28) mm, glandular-pubescent internally in 2 lines on abaxial surface, tube 3–4 mm, throat 3–5 mm diam.;

stamens included, pollen sacs 0.5–0.6 mm;

staminode 7–9 mm;

style 8–10 mm.

Capsules

9–12 × 5–7 mm.

6–9 × 3–5 mm.

Seeds

3.5–5 mm.

Penstemon lentus

Penstemon ambiguus

Distribution
from FNA
AZ; CO; NM; UT
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CO; KS; NE; NM; NV; OK; TX; UT; n Mexico
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 2 (2 in the flora).

Penstemon lentus is found in the Four Corners region of the Colorado Plateau. Reported differences (N. H. Holmgren 1984) between the two varieties in the sizes of the pollen sacs appear to be inconsistent and not taxonomically useful.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Varieties 2 (2 in the flora).

G. T. Nisbet and R. C. Jackson (1960) reported natural hybrids between Penstemon ambiguus and P. thurberi from Lincoln and Socorro counties, New Mexico.

Some Native American tribes used Penstemon ambiguus as a drug or ceremonial plant (D. E. Moerman 1998).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Corollas lavender to violet, blue, or pinkish blue; Arizona, Colorado, New Mexico, Utah.
var. lentus
1. Corollas white; San Juan County, Utah.
var. albiflorus
1. Stems scabrous proximally; leaf blade margins scabrous.
var. ambiguus
1. Stems glabrous; leaf blade margins glabrous or scabrous.
var. laevissimus
Source FNA vol. 17, p. 120. FNA vol. 17, p. 95.
Parent taxa Plantaginaceae > Penstemon > subg. Penstemon > sect. Coerulei Plantaginaceae > Penstemon > subg. Penstemon > sect. Ambigui
Sibling taxa
P. abietinus, P. absarokensis, P. acaulis, P. acuminatus, P. alamosensis, P. albertinus, P. albidus, P. albomarginatus, P. ambiguus, P. ammophilus, P. anguineus, P. angustifolius, P. arenarius, P. arenicola, P. aridus, P. arkansanus, P. attenuatus, P. atwoodii, P. auriberbis, P. australis, P. azureus, P. baccharifolius, P. barbatus, P. barnebyi, P. barrettiae, P. bicolor, P. bleaklyi, P. bracteatus, P. breviculus, P. brevisepalus, P. buckleyi, P. caesius, P. caespitosus, P. calcareus, P. californicus, P. calycosus, P. canescens, P. cardinalis, P. cardwellii, P. carnosus, P. caryi, P. centranthifolius, P. cinicola, P. clevelandii, P. clutei, P. cobaea, P. comarrhenus, P. compactus, P. concinnus, P. confertus, P. confusus, P. crandallii, P. cusickii, P. cyananthus, P. cyaneus, P. cyanocaulis, P. cyathophorus, P. dasyphyllus, P. davidsonii, P. deamii, P. deaveri, P. debilis, P. degeneri, P. deustus, P. digitalis, P. diphyllus, P. discolor, P. dissectus, P. distans, P. dolius, P. duchesnensis, P. eatonii, P. elegantulus, P. ellipticus, P. eriantherus, P. euglaucus, P. fendleri, P. filiformis, P. flavescens, P. floribundus, P. floridus, P. flowersii, P. franklinii, P. fremontii, P. fruticiformis, P. fruticosus, P. gairdneri, P. gibbensii, P. glaber, P. glandulosus, P. glaucinus, P. globosus, P. goodrichii, P. gormanii, P. gracilentus, P. gracilis, P. grahamii, P. grandiflorus, P. griffinii, P. grinnellii, P. guadalupensis, P. hallii, P. harbourii, P. harringtonii, P. havardii, P. haydenii, P. heterodoxus, P. heterophyllus, P. hirsutus, P. humilis, P. idahoensis, P. immanifestus, P. incertus, P. inflatus, P. jamesii, P. janishiae, P. kingii, P. kralii, P. labrosus, P. laetus, P. laevigatus, P. laevis, P. lanceolatus, P. laricifolius, P. laxiflorus, P. laxus, P. leiophyllus, P. lemhiensis, P. leonardii, P. linarioides, P. longiflorus, P. lyallii, P. marcusii, P. mensarum, P. metcalfei, P. miser, P. moffatii, P. monoensis, P. montanus, P. moriahensis, P. mucronatus, P. multiflorus, P. murrayanus, P. nanus, P. navajoa, P. neomexicanus, P. neotericus, P. newberryi, P. nitidus, P. nudiflorus, P. oklahomensis, P. oliganthus, P. ophianthus, P. osterhoutii, P. ovatus, P. pachyphyllus, P. pahutensis, P. pallidus, P. palmeri, P. papillatus, P. parryi, P. parvulus, P. parvus, P. patens, P. payettensis, P. paysoniorum, P. peckii, P. penlandii, P. pennellianus, P. perpulcher, P. personatus, P. petiolatus, P. pinifolius, P. pinorum, P. platyphyllus, P. pratensis, P. procerus, P. pruinosus, P. pseudoputus, P. pseudospectabilis, P. pudicus, P. pumilus, P. purpusii, P. putus, P. radicosus, P. rattanii, P. retrorsus, P. rhizomatosus, P. richardsonii, P. roezlii, P. rostriflorus, P. rubicundus, P. rupicola, P. rydbergii, P. saxosorum, P. scapoides, P. scariosus, P. secundiflorus, P. seorsus, P. sepalulus, P. serrulatus, P. smallii, P. spatulatus, P. speciosus, P. spectabilis, P. stenophyllus, P. stephensii, P. strictiformis, P. strictus, P. subglaber, P. subserratus, P. subulatus, P. sudans, P. superbus, P. tenuiflorus, P. tenuis, P. teucrioides, P. thompsoniae, P. thurberi, P. tidestromii, P. tiehmii, P. tracyi, P. triflorus, P. triphyllus, P. tubaeflorus, P. uintahensis, P. utahensis, P. venustus, P. virens, P. virgatus, P. wardii, P. washingtonensis, P. watsonii, P. whippleanus, P. wilcoxii, P. wrightii, P. xylus, P. yampaënsis
P. abietinus, P. absarokensis, P. acaulis, P. acuminatus, P. alamosensis, P. albertinus, P. albidus, P. albomarginatus, P. ammophilus, P. anguineus, P. angustifolius, P. arenarius, P. arenicola, P. aridus, P. arkansanus, P. attenuatus, P. atwoodii, P. auriberbis, P. australis, P. azureus, P. baccharifolius, P. barbatus, P. barnebyi, P. barrettiae, P. bicolor, P. bleaklyi, P. bracteatus, P. breviculus, P. brevisepalus, P. buckleyi, P. caesius, P. caespitosus, P. calcareus, P. californicus, P. calycosus, P. canescens, P. cardinalis, P. cardwellii, P. carnosus, P. caryi, P. centranthifolius, P. cinicola, P. clevelandii, P. clutei, P. cobaea, P. comarrhenus, P. compactus, P. concinnus, P. confertus, P. confusus, P. crandallii, P. cusickii, P. cyananthus, P. cyaneus, P. cyanocaulis, P. cyathophorus, P. dasyphyllus, P. davidsonii, P. deamii, P. deaveri, P. debilis, P. degeneri, P. deustus, P. digitalis, P. diphyllus, P. discolor, P. dissectus, P. distans, P. dolius, P. duchesnensis, P. eatonii, P. elegantulus, P. ellipticus, P. eriantherus, P. euglaucus, P. fendleri, P. filiformis, P. flavescens, P. floribundus, P. floridus, P. flowersii, P. franklinii, P. fremontii, P. fruticiformis, P. fruticosus, P. gairdneri, P. gibbensii, P. glaber, P. glandulosus, P. glaucinus, P. globosus, P. goodrichii, P. gormanii, P. gracilentus, P. gracilis, P. grahamii, P. grandiflorus, P. griffinii, P. grinnellii, P. guadalupensis, P. hallii, P. harbourii, P. harringtonii, P. havardii, P. haydenii, P. heterodoxus, P. heterophyllus, P. hirsutus, P. humilis, P. idahoensis, P. immanifestus, P. incertus, P. inflatus, P. jamesii, P. janishiae, P. kingii, P. kralii, P. labrosus, P. laetus, P. laevigatus, P. laevis, P. lanceolatus, P. laricifolius, P. laxiflorus, P. laxus, P. leiophyllus, P. lemhiensis, P. lentus, P. leonardii, P. linarioides, P. longiflorus, P. lyallii, P. marcusii, P. mensarum, P. metcalfei, P. miser, P. moffatii, P. monoensis, P. montanus, P. moriahensis, P. mucronatus, P. multiflorus, P. murrayanus, P. nanus, P. navajoa, P. neomexicanus, P. neotericus, P. newberryi, P. nitidus, P. nudiflorus, P. oklahomensis, P. oliganthus, P. ophianthus, P. osterhoutii, P. ovatus, P. pachyphyllus, P. pahutensis, P. pallidus, P. palmeri, P. papillatus, P. parryi, P. parvulus, P. parvus, P. patens, P. payettensis, P. paysoniorum, P. peckii, P. penlandii, P. pennellianus, P. perpulcher, P. personatus, P. petiolatus, P. pinifolius, P. pinorum, P. platyphyllus, P. pratensis, P. procerus, P. pruinosus, P. pseudoputus, P. pseudospectabilis, P. pudicus, P. pumilus, P. purpusii, P. putus, P. radicosus, P. rattanii, P. retrorsus, P. rhizomatosus, P. richardsonii, P. roezlii, P. rostriflorus, P. rubicundus, P. rupicola, P. rydbergii, P. saxosorum, P. scapoides, P. scariosus, P. secundiflorus, P. seorsus, P. sepalulus, P. serrulatus, P. smallii, P. spatulatus, P. speciosus, P. spectabilis, P. stenophyllus, P. stephensii, P. strictiformis, P. strictus, P. subglaber, P. subserratus, P. subulatus, P. sudans, P. superbus, P. tenuiflorus, P. tenuis, P. teucrioides, P. thompsoniae, P. thurberi, P. tidestromii, P. tiehmii, P. tracyi, P. triflorus, P. triphyllus, P. tubaeflorus, P. uintahensis, P. utahensis, P. venustus, P. virens, P. virgatus, P. wardii, P. washingtonensis, P. watsonii, P. whippleanus, P. wilcoxii, P. wrightii, P. xylus, P. yampaënsis
Subordinate taxa
P. lentus var. albiflorus, P. lentus var. lentus
P. ambiguus var. ambiguus, P. ambiguus var. laevissimus
Name authority Pennell: Contr. U.S. Natl. Herb. 20: 359. (1920) Torrey: Ann. Lyceum Nat. Hist. New York 2: 228. (1827) — (as Pentstemon ambiguum)
Web links