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glaucous beardtongue, glaucous penstemon

foxglove beard-tongue, penstémon digitale, tall white beardtongue, talus slope penstemon

Habit Herbs. Herbs.
Stems

ascending to erect, 15–55 cm, glabrous, glaucous.

erect, 25–90 cm, glabrous or sparsely retrorsely hairy, slightly glaucous or not.

Leaves

basal and cauline, ± leathery or not, glabrous, glaucous;

basal and proximal cauline (15–)30–115 × 4–25 mm, blade elliptic to oblanceolate or spatulate, base tapered, margins entire, apex obtuse to acute;

cauline 3–6 pairs, sessile or proximals short-petiolate, (17–)40–72 × 9–28 mm, blade ovate to lanceolate, base tapered to clasping, margins entire, apex obtuse to acute.

basal and cauline, basal sometimes withering by anthesis, not leathery, glabrous;

basal and proximal cauline 30–180(–250) × 4–38(–70) mm, blade spatulate to obovate or lanceolate, base tapered, margins entire or ± serrate or denticulate, apex rounded to obtuse or acute;

cauline 5–8 pairs, petiolate or sessile, 26–195 × 4–55 mm, blade ovate to lanceolate, base tapered to clasping, margins entire or denticulate, apex acuminate to acute.

Thyrses

continuous or interrupted, cylindric, 2–21 cm, axis glabrous, verticillasters 1–6, cymes (2 or)3–8-flowered, 2 per node;

proximal bracts lanceolate, 9–45 × 4–13 mm, margins entire;

peduncles and pedicels erect, glabrous.

interrupted, conic, 7–26(–34) cm, axis glabrous proximally, sparsely to densely glandular-pubescent distally, verticillasters (2 or)3–6, cymes (3–)5–12(–18)-flowered, 2 per node;

proximal bracts lanceolate to linear, 9–105 × 1–40 mm, margins entire, sometimes serrulate;

peduncles and pedicels spreading to ascending, sparsely glandular-pubescent.

Flowers

calyx lobes ovate to lanceolate, 2.5–4.5 × 1–2.4 mm, glabrous;

corolla violet to blue or purple, with light violet nectar guides, funnelform, 11–15 mm, glabrous externally, sparsely whitish or yellowish pubescent internally abaxially, tube 3–4 mm, throat gradually inflated, 3.5–5 mm diam., 2-ridged abaxially;

stamens: longer pair exserted, pollen sacs opposite, navicular, 0.5–0.7 mm, dehiscing completely, connective splitting, sides glabrous, sutures smooth;

staminode 7–8 mm, reaching orifice, 0.2–0.3 mm diam., tip straight to slightly recurved, distal 0.5–2 mm sparsely to densely pilose, hairs golden yellow, to 0.8 mm;

style 8–10 mm.

calyx lobes ovate, sometimes lanceolate, 4–8 × 2–3 mm, apex acute to acuminate, glandular-pubescent;

corolla white, sometimes tinged lavender, with reddish purple nectar guides, ventricose, (17–)20–30 mm, glandular-pubescent externally, sparsely to moderately white-pubescent internally abaxially, tube 6–9 mm, throat abruptly inflated, 8–12 mm diam., slightly 2-ridged abaxially;

stamens included or longer pair reaching orifice, pollen sacs opposite, navicular, 1.4–1.7 mm, dehiscing completely, connective splitting, sides sparsely pubescent, hairs white or purplish, to 0.6 mm, rarely glabrous, sutures papillate;

staminode 13–17 mm, reaching orifice, 0.3–0.4 mm diam., tip straight to slightly recurved, distal 6–8 mm sparsely to moderately villous, hairs yellowish, to 1.5(–2) mm;

style 13–18 mm.

Capsules

5–6 × 3.5–4.5 mm, glabrous.

8–14 × 4–6 mm, glabrous.

2n

= 48.

= 96.

Penstemon euglaucus

Penstemon digitalis

Phenology Flowering Jun–Sep. Flowering Apr–Jul.
Habitat Sandy, open pine forests, subalpine meadows. Prairies, meadows, roadsides, clearings in woods.
Elevation 1200–2400 m. (3900–7900 ft.) 10–500 m. (0–1600 ft.)
Distribution
from FNA
OR; WA
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; CT; DC; DE; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; NE; NH; NJ; NY; OH; OK; PA; RI; SC; SD; TN; TX; VA; VT; WI; WV; NB; NS; ON; QC
[WildflowerSearch map]
[BONAP county map]
Discussion

Penstemon euglaucus is a hexaploid of the Cascade Range from Three Sisters, Oregon, north to Mount Adams, Washington. A chromosome count of 2n = 16 (P. G. Zhukova 1967) is inconsistent with earlier reports of 2n = 48 (J. Clausen et al. 1940; D. D. Keck 1945) and likely is in error.

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

Penstemon digitalis appears to be native in the central Mississippi River Basin, with human activities expanding its range, particularly eastward (F. W. Pennell 1935). It is listed in VASCAN as introduced in the four Canadian provinces where it occurs (http://data.canadensys.net/vascan/taxon/7273).

Plants resembling Penstemon digitalis but with smaller corollas (17–23 mm versus 23–30 mm), less glandular-pubescent inflorescences, less scarious-margined calyx lobes, and stems sometimes puberulent (versus glabrous) have been named P. alluviorum. Plants with those features come mostly from the southeastern Central Lowlands and north-central Coastal Plain provinces in the eastern United States in the south-central part of the range of P. digitalis (Alabama, Arkansas, Illinois, Indiana, Kentucky, Mississippi, Missouri, Ohio, and Tennessee). A. C. Koelling (1964) observed overlap in characters used to distinguish P. alluviorum from P. digitalis and concluded it was a small-flowered variant of P. digitalis.

Specimens of Penstemon digitalis with lanceolate and acuminate-tipped calyx lobes can be mistaken for P. calycosus, but calyx lobe length and, usually, the presence of hairs on the pollen sacs allow them to be accurately identified.

Penstemon digitalis is widely cultivated and spreads readily. R. R. Clinebell and P. Bernhardt (1998) found evidence that plants are self-compatible.

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

Source FNA vol. 17, p. 203. FNA vol. 17, p. 202.
Parent taxa Plantaginaceae > Penstemon > subg. Penstemon > sect. Penstemon Plantaginaceae > Penstemon > subg. Penstemon > sect. Penstemon
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. 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. 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
Synonyms P. alluviorum
Name authority English: Proc. Biol. Soc. Wash. 41: 197. (1928) Nuttall ex Sims: Bot. Mag. 52: plate 2587. (1825) — (as Pentstemon)
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