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azure beardtongue, azure penstemon, blue penstemon

dusty beardtongue, dusty penstemon

Habit Subshrubs.
Stems

ascending to erect, 13–50(–70) cm, glabrous, glaucous.

ascending to erect, (18–)40–80(–120) cm, glabrous, sometimes retrorsely hairy proximally, not glaucous.

Leaves

basal and cauline, basal sometimes few, opposite, glabrous, glaucous;

basal and proximal cauline 15–60 × 2–10(–20) mm, blade obovate to oblanceolate or linear, base tapered, margins entire, apex obtuse to acute;

cauline 3–20 pairs, sessile or proximals short-petiolate, 10–90 × 2–20 mm, blade elliptic to ovate, lanceolate, or linear, base tapered to clasping or cordate-clasping, margins entire, apex obtuse to acute.

basal and cauline, ± leathery or not, glabrous or sparsely retrorsely hairy, rarely densely retrorsely hairy, not glaucous;

basal and proximal cauline 40–80(–120) × 7–20(–30) mm, blade obovate to oblanceolate, base tapered, margins entire, apex obtuse to acute;

cauline 5–7(or 8) pairs, sessile, 38–110 × 1–10 mm, blade oblanceolate to linear, base tapered, apex obtuse to acute.

Thyrses

interrupted or continuous, secund, (3–)6–31 cm, axis glabrous, verticillasters 3–10, cymes 1–3(or 4)-flowered, 2 per node;

proximal bracts ovate to lanceolate, 4–50 × 1–32 mm;

peduncles and pedicels ascending to erect, glabrous.

erupted, secund, sometimes subsecund, (12–)15–32 cm, axis glabrous, verticillasters 6–12, cymes 1–2(–5)-flowered, 2 per node;

proximal bracts linear, (6–)26–84 × 1–4 mm;

peduncles and pedicels glabrous.

Flowers

calyx lobes ovate to oblong or obovate, 2.5–6.5 × 1.4–3.2 mm, glabrous;

corolla violet to blue or purple, with or without purple nectar guides, funnelform to ventricose, 18–35 mm, glabrous externally, glabrous internally, tube 7–9 mm, throat gradually inflated, 8–10 mm diam., slightly 2-ridged abaxially;

stamens: longer pair reaching orifice or exserted, filaments glabrous, pollen sacs parallel, 1.8–3.5 mm, distal 1/3–1/2 indehiscent, sides hispidulous to pilose, hairs white, to 0.8 mm near filament attachment, sutures denticulate, teeth to 0.3 mm;

staminode 12–19 mm, included, 0.4–0.6 mm diam., glabrous;

style 16–22 mm.

calyx lobes ovate, (2.2–)3.5–6(–7) × 2.1–2.7 mm, glabrous;

corolla blue to pinkish blue or lavender, with violet nectar guides, ventricose, 25–35(–38) mm, glabrous externally, glabrous internally, tube 8–11(–14) mm, throat abruptly inflated, slightly constricted at orifice, 9–13 mm diam., slightly 2-ridged abaxially;

stamens: longer pair exserted, pollen sacs divergent to nearly opposite, navicular-sigmoid, 2–2.5(–2.8) mm, dehiscing incompletely, proximal 1/5 indehiscent, connective not splitting, sides densely villous or lanate, hairs white, to 2.5 mm, sutures smooth, papillate, or denticulate, teeth to 0.1 mm;

staminode 12–17 mm, included, 0.8–1 mm diam., tip straight, glabrous or distal 1–2 mm sparsely pilose, hairs white, to 0.5 mm;

style 16–25 mm.

Capsules

7–11 × 14–6 mm.

(7–)10–15 × 4–5 mm.

Penstemon azureus

Penstemon comarrhenus

Phenology Flowering Jun–Aug.
Habitat Pinyon-juniper, Gambel oak, and ponderosa pine woodlands.
Elevation (1000–)1600–2800 m. ((3300–)5200–9200 ft.)
Distribution
from FNA
CA; OR
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CO; NM; NV; UT
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 2 (2 in the flora).

Penstemon azureus occurs from southwestern Oregon to central California.

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

Penstemon comarrhenus usually is distinguished from P. strictus by its paler blue corollas, more diffuse inflorescences, and more densely lanate anthers. A putative hybrid between P. comarrhenus and P. barbatus var. trichander has been collected in La Plata County, Colorado (R. E. Umber, B. E. Nelson & T. Davis 999b, KANU, RM).

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

Key
1. Calyx lobes obovate to oblong, 2.5–4.8 × 2–3.2 mm, apices cuspidate to mucronate; cauline leaves 10–65 × 4–20 mm, blades elliptic to ovate or lanceolate.
var. azureus
1. Calyx lobes ovate, 5–6.5 × 1.4–2.3 mm, apices acuminate to caudate; cauline leaves 40–90 × 2–6 mm, blades lanceolate to linear.
var. angustissimus
Source FNA vol. 17, p. 231. FNA vol. 17, p. 162.
Parent taxa Plantaginaceae > Penstemon > subg. Penstemon > sect. Saccanthera Plantaginaceae > Penstemon > subg. Penstemon > sect. Glabri
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. 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
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. 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. azureus var. angustissimus, P. azureus var. azureus
Name authority Bentham: Pl. Hartw., 327. (1849) — (as Pentstemon) A. Gray: Proc. Amer. Acad. Arts 12: 81. (1876) — (as Pentstemon)
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