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azure beardtongue, azure penstemon, blue penstemon

little-cup beardtongue

Habit Subshrubs. Herbs or subshrubs.
Stems

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

ascending to erect, 40–90 cm, glabrous, 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.

cauline, opposite, glabrous, glaucous;

cauline 6–14 pairs, sessile, 30–85(–102) × 3–13 mm, blade elliptic, base tapered, margins entire, apex 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.

interrupted, cylindric, 6–30 cm, axis glabrous, verticillasters (5–)8–14, cymes 1(or 2)-flowered, 2 per node;

proximal bracts narrowly elliptic to linear, 8–45 × 1–8 mm;

peduncles and pedicels ascending to erect, 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 obovate to ovate or elliptic, 1.8–3.2 × 1.5–2.2 mm, glabrous or minutely ciliolate distally;

corolla light lavender to violet or purple, with violet nectar guides, weakly ventricose, 22–26(–28) mm, glabrous externally, glabrous internally, tube 7–9 mm, throat gradually inflated, 7–9 mm diam., 2-ridged abaxially;

stamens included or longer pair exserted, filaments glabrous, pollen sacs parallel to slightly divergent, 1.5–2 mm, distal 2/3 indehiscent, sides glabrous, sutures denticulate, teeth to 0.1 mm;

staminode 15–16 mm, included, 0.5–0.6 mm diam., glabrous;

style 16–20 mm.

Capsules

7–11 × 14–6 mm.

7–10 × 4.5–5.5 mm.

Penstemon azureus

Penstemon sepalulus

Phenology Flowering Jun–Aug.
Habitat Rocky to gravelly and talus slopes, Gambel oak, maple, and aspen woodlands.
Elevation 1200–2300 m. (3900–7500 ft.)
Distribution
from FNA
CA; OR
[WildflowerSearch map]
[BONAP county map]
from FNA
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 sepalulus is found in the Wasatch Mountains in Juab, Sevier, Utah, and Washington counties.

(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. 243.
Parent taxa Plantaginaceae > Penstemon > subg. Penstemon > sect. Saccanthera Plantaginaceae > Penstemon > subg. Penstemon > sect. Saccanthera
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. 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. 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
Synonyms P. azureus var. ambiguus
Name authority Bentham: Pl. Hartw., 327. (1849) — (as Pentstemon) A. Nelson: in J. M. Coulter and A. Nelson, New Man. Bot. Rocky Mt., 449. (1909) — (as Pentstemon)
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