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white beardtongue, white penstemon

thread-leaf beardtongue

Habit Herbs or subshrubs.
Stems

ascending to erect, (10–)15–50(–55) cm, retrorsely hairy proximally, glandular-pubescent distally.

ascending to erect, 16–50 cm, puberulent to retrorsely hairy, hairs pointed, not glaucous.

Leaves

basal and cauline, not leathery, glabrate or puberulent to scabrous;

basal and proximal cauline petiolate, 20–85(–110) × (4–)7–18(–20) mm, blade oblanceolate or obovate to lanceolate, base tapered, margins entire to obscurely or distinctly serrate, apex obtuse to acute;

cauline 2–5(or 6) pairs, sessile or proximals short-petiolate, 25–65 × (3–)7–19(–21) mm, blade ovate to lanceolate, base tapered to clasping, margins entire or serrate to dentate, apex acute.

cauline, opposite, puberulent, hairs pointed, or glabrous, not glaucous;

cauline 8–12 pairs, sessile, 12–70 × 0.5–1(–2) mm, blade linear, base not tapered, margins entire, apex acute.

Thyrses

continuous or interrupted, cylindric, 4–24(–30) cm, axis densely glandular-pubescent, verticillasters (2 or)3–10, cymes 2–7-flowered, 2 per node;

proximal bracts lanceolate, 17–65 × 3–17 mm;

peduncles and pedicels densely glandular-pubescent.

interrupted, cylindric, 9–22 cm, axis glandular-pubescent, verticillasters 1–5, cymes 1–3-flowered, (1 or)2 per node;

proximal bracts linear, 9–30 × 0.5–1 mm;

peduncles and pedicels spreading to ascending, glandular-pubescent.

Flowers

calyx lobes ovate to lanceolate, 4–7 × 1.5–3 mm, glandular-pubescent;

corolla white, rarely tinged pink or lavender, with red or reddish purple nectar guides, funnelform, (12–)16–20 mm, glandular-pubescent internally, tube 4–6 mm, throat gradually inflated, not constricted at orifice, (4–)6–8 mm diam., rounded abaxially;

stamens included, pollen sacs opposite, explanate, 0.7–1.1 mm, dehiscing completely, sutures smooth;

staminode 8–9 mm, included, 0.3–0.4 mm diam., tip straight to recurved, distal 3–6 mm sparsely to moderately villous, hairs yellowish, to 1 mm;

style 9–11(–13) mm.

calyx lobes ovate to lanceolate, 2–4.5 × 0.7–1.7 mm, glandular-pubescent;

corolla light purple to violet or purple, without nectar guides, funnelform, 13–18 mm, glandular-pubescent externally, glabrous internally, tube 3–4 mm, throat gradually inflated, 5–7 mm diam., 2-ridged abaxially;

stamens included or longer pair reaching orifice, filaments glabrous, pollen sacs parallel, 1.2–1.6 mm, distal 1/2 indehiscent, sides pubescent, hairs white, to 0.5 mm near filament attachment, sutures denticulate, teeth to 0.2 mm;

staminode 10–12 mm, included or reaching orifice, 0.3–0.5 mm diam., glabrous;

style 11–15 mm.

Capsules

8–12 × 4–7 mm.

5–7.5 × 2.5–4 mm.

2n

= 16.

= 16.

Penstemon albidus

Penstemon filiformis

Phenology Flowering Apr–Jul(–Sep). Flowering Jun–Jul.
Habitat Silty or gravelly soils, mixed-grass and shortgrass prairies. Rocky shrublands, pine woodlands.
Elevation 300–1800 m. (1000–5900 ft.) 400–600 m. (1300–2000 ft.)
Distribution
from FNA
CO; IA; KS; MN; MT; ND; NE; NM; OK; SD; TX; WY; AB; MB; ON; SK
[WildflowerSearch map]
[BONAP county map]
from FNA
CA
[BONAP county map]
Discussion

Penstemon albidus is remarkably uniform throughout its range. It probably is introduced in Ontario.

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

Penstemon filiformis is known from Lake, Shasta, Siskiyou, and Trinity counties.

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

Source FNA vol. 17, p. 128. FNA vol. 17, p. 233.
Parent taxa Plantaginaceae > Penstemon > subg. Penstemon > sect. Cristati Plantaginaceae > Penstemon > subg. Penstemon > sect. Saccanthera
Sibling taxa
P. abietinus, P. absarokensis, P. acaulis, P. acuminatus, P. alamosensis, P. albertinus, 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. 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. 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. laetus subsp. filiformis
Name authority Nuttall: Gen. N. Amer. Pl. 2: 53. (1818) — (as Pentstemon albidum) (D. D. Keck) D. D. Keck: in L. Abrams and R. S. Ferris, Ill. Fl. Pacific States 3: 761. (1951)
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