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azure beardtongue, azure penstemon, blue penstemon

Steptoe Valley beardtongue, Steptoe Valley penstemon

Habit Subshrubs.
Stems

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

ascending to erect, 9–30(–35) cm, glabrous.

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, basal not reduced, glabrous;

basal and proximal cauline 15–60(–90) × 8–25(–39) mm, blade oblanceolate to obovate, base tapered, apex rounded to obtuse, sometimes mucronate;

cauline 3–7 pairs, short-petiolate or sessile, (25–)35–80 × 10–20(–28) mm, blade lanceolate to ovate, base tapered to clasping, 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.

continuous or interrupted, cylindric, (4–)6–20 cm, axis glabrous, verticillasters (3–)5–10(–14), cymes 2–5-flowered;

proximal bracts ovate to lanceolate, (5–)13–56 × (2–)4–24 mm;

peduncles and pedicels glabrous, peduncles to 12 mm.

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, 5–8(–12) × 2–3.5 mm, margins entire or erose, broadly scarious, apex acuminate, glabrous;

corolla bluish lavender to lavender or pink, with dark reddish violet or reddish nectar guides, funnelform to ventricose, 15–22 mm, glabrous externally, sparsely white-villous internally abaxially or glabrous, tube 5–7 mm, throat gradually inflated, 5–8 mm diam., rounded abaxially;

stamens included, pollen sacs opposite, (1–)1.2–1.6 mm, sutures papillate;

staminode 8–10 mm, included or reaching orifice, 0.7–1 mm diam., tip strongly recurved, distal 2–5 mm densely villous, hairs yellowish, brownish, or orangish, to 1 mm;

style 10–12 mm.

Capsules

7–11 × 14–6 mm.

8–12 × 4–6 mm.

Seeds

2–4 mm.

Penstemon azureus

Penstemon immanifestus

Phenology Flowering May–Jun.
Habitat Sandy or sandy-loam soils, sagebrush grasslands.
Elevation 1500–2200 m. (4900–7200 ft.)
Distribution
from FNA
CA; OR
[WildflowerSearch map]
[BONAP county map]
from FNA
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 immanifestus occurs along the western edge of the Bonneville Basin in eastern Nevada and western Utah, and in the Calcareous Mountains, central Great Basin, and Tonopah regions of eastern and central Nevada. Populations have been documented in Elko, Eureka, Lander, Nye, and White Pine counties, Nevada, and in Juab, Millard, and Tooele counties, Utah.

(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. 120.
Parent taxa Plantaginaceae > Penstemon > subg. Penstemon > sect. Saccanthera Plantaginaceae > Penstemon > subg. Penstemon > sect. Coerulei
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. 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. 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) N. H. Holmgren: Brittonia 30: 334, fig. 1. (1978)
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