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two-leaf beardtongue

Navajo beardtongue, Navajo Mountain beardtongue

Habit Subshrubs.
Stems

ascending to erect, (10–)20–80 cm, retrorsely hairy, not glaucous.

ascending to erect, 15–65 cm, glabrous, not glaucous.

Leaves

cauline, opposite, sometimes alternate, glabrous, not glaucous;

cauline (4–)7–10 pairs, sessile or proximals short-petiolate, 20–80 × 5–17 mm, blade elliptic to lanceolate or oblanceolate, base tapered, margins irregularly dentate or serrate, apex acute.

basal and cauline, not leathery, glabrous or retrorsely hairy, not glaucous;

basal and proximal cauline 12–80 × 4–10(–15) mm, blade spatulate to oblanceolate or lanceolate, base tapered, margins entire, apex rounded to obtuse, or acute;

cauline 3 or 4 pairs, sessile, 12–50(–75) × 1–5 mm, blade oblanceolate to linear, base tapered, apex acute to acuminate.

Thyrses

interrupted, cylindric, 3–25(–50) cm, axis glandular-pubescent, verticillasters 4–10, cymes 1–11(–18)-flowered, 1 or 2 per node;

proximal bracts lanceolate, rarely ovate, 9–45 × 2–16 mm;

peduncles and pedicels spreading to ascending, glandular-pubescent.

interrupted, secund, 2–25(–47) cm, axis glabrous, verticillasters 4–14, cymes 1- or 2(or 3)-flowered, 1 or 2 per node;

proximal bracts linear, 6–15(–68) × 1–2 mm;

peduncles and pedicels glabrous.

Flowers

calyx lobes lanceolate, (2–)3–5.2 × 0.9–1.3 mm, glandular-pubescent;

corolla bluish lavender to violet or purple, with reddish purple nectar guides, funnelform, 13–19 mm, glandular-pubescent externally, glabrous internally or sparsely white-lanate abaxially, tube 5–6 mm, throat gradually inflated, 5–6 mm diam., rounded abaxially;

stamens included, filaments glabrous or sparsely white-pubescent distally, pollen sacs parallel, 0.9–1.3 mm, distal 1/2 indehiscent, sides glabrous, sutures denticulate, teeth to 0.1 mm;

staminode 9–11 mm, reaching orifice or barely exserted, 0.4–0.5 mm diam., distal 1–4 mm sparsely to moderately lanate, hairs white or yellowish, to 1.5 mm;

style 8–12 mm.

calyx lobes ovate, 2.6–4 × 1.5–2.2 mm, glabrous;

corolla blue to lavender, with faint reddish purple nectar guides, ventricose, 18–23(–25) mm, glabrous externally, sparsely white-villous internally abaxially, tube 7–9 mm, throat gradually to abruptly inflated, not constricted at orifice, 7–10 mm diam., slightly 2-ridged abaxially;

stamens reaching orifice or longer pair slightly exserted, pollen sacs opposite, navicular, 1.2–1.8 mm, dehiscing incompletely, proximal 1/5 sometimes indehiscent, connective not splitting, sides lanate, rarely glabrous, hairs white, to 0.9 mm, sutures denticulate, teeth to 0.1 mm;

staminode 9–11 mm, reaching orifice, 0.5–0.7 mm diam., tip straight, glabrous;

style 12–17 mm.

Capsules

4–6 × 2.8–4.5 mm.

6.9–13 × 4.5–6.5 mm.

Penstemon diphyllus

Penstemon navajoa

Phenology Flowering Jun–Aug(–Sep). Flowering Jul–Aug.
Habitat Talus slopes, cliffs, rocky banks. Rocky ponderosa pine, aspen, Douglas fir, and subalpine fir forests.
Elevation 1000–2300 m. (3300–7500 ft.) 2500–3200 m. (8200–10500 ft.)
Distribution
from FNA
ID; MT; WA
[WildflowerSearch map]
[BONAP county map]
from FNA
UT
[BONAP county map]
Discussion

Penstemon diphyllus occurs in northeastern Idaho, western Montana, and southeastern Washington (Whitman County).

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

Penstemon navajoa is known from the Abajo Mountains, upper Dark Canyon, and Navajo Mountain in San Juan County.

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

Source FNA vol. 17, p. 232. FNA vol. 17, p. 173.
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. 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. 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. 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
Name authority Rydberg: Mem. New York Bot. Gard. 1: 349. (1900) — (as Pentstemon) N. H. Holmgren: Brittonia 30: 419, fig. 3. (1978)
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