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white beardtongue, white penstemon

Rydberg's beardtongue, Rydberg's penstemon

Habit Herbs.
Stems

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

decumbent, ascending, or erect, 20–70(–120) cm, glabrous or retrorsely hairy, sometimes only in lines, 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.

basal and cauline, not leathery, glabrous;

basal and proximal cauline (25–)35–70(–150) × (5–)10–15(–22) mm, blade oblanceolate to elliptic, base tapered, margins entire, apex obtuse to acute, rarely mucronate;

cauline 3–6 pairs, sessile or proximals short-petiolate, 25–70(–110) × 3–24 mm, blade lanceolate to elliptic or oblong, base tapered to clasping, margins entire, apex obtuse to 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, 3–10(–18) cm, axis retrorsely hairy or puberulent, sometimes glabrous, verticillasters (1 or)2–7, cymes (3–)5–11-flowered, 2 per node;

proximal bracts lanceolate, (4–)11–52(–70) × (1–)2–18 mm, margins entire or erose to lacerate;

peduncles and pedicels erect, glabrous, retrorsely hairy, or puberulent.

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 oblong to ovate or obovate, 3–8 × 1.2–3.5 mm, apex acute to acuminate or short- to long-caudate, glabrous or puberulent;

corolla violet to blue or purple, without nectar guides, funnelform, 10–20 mm, glabrous externally, sparsely white- or yellowish villous internally abaxially, tube 3–4 mm, throat gradually inflated, 3–4.5 mm diam., 2-ridged abaxially;

stamens: longer pair reaching orifice or exserted, pollen sacs opposite, navicular, 0.5–1.1 mm, dehiscing completely, connective splitting, sides glabrous, sutures smooth or ± papillate;

staminode 6–7 mm, reaching orifice, 0.2–0.4 mm diam., tip straight, distal 1.5–2 mm moderately to densely pilose, hairs golden yellow, to 1 mm;

style 8–10 mm.

Capsules

8–12 × 4–7 mm.

4–5 × 3–4 mm, glabrous.

2n

= 16.

Penstemon albidus

Penstemon rydbergii

Phenology Flowering Apr–Jul(–Sep).
Habitat Silty or gravelly soils, mixed-grass and shortgrass prairies.
Elevation 300–1800 m. (1000–5900 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
AZ; CA; CO; ID; MT; NM; NV; OR; UT; WA; WY
[WildflowerSearch map]
[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.)

Varieties 3 (3 in the flora).

As treated here, Penstemon rydbergii includes three partially sympatric varieties. D. D. Keck (1945) treated the same taxa as four species and two subspecies (P. hesperius, P. oreocharis, P. rydbergii subsp. aggregatus, P. rydbergii subsp. rydbergii, and P. vaseyanus).

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

Key
1. Calyx lobe margins lacerate, rarely erose, broadly scarious, apices acuminate or short- to long-caudate; proximal bract margins erose to lacerate proximally, sometimes entire; thyrse axes retrorsely hairy or puberulent.
var. rydbergii
1. Calyx lobe margins erose, sometimes lacerate, narrowly to broadly scarious, apices acute, acuminate, or short-caudate; proximal bract margins entire; thyrse axes glabrous or retrorsely hairy.
→ 2
2. Stems ± retrorsely hairy; thyrse axes glabrous or retrorsely hairy; corollas (10–)13–20 mm; pollen sacs (0.6–)0.8–1.1 mm.
var. aggregatus
2. Stems glabrous, rarely ± retrorsely hairy; thyrse axes glabrous, rarely ± retrorsely hairy; corollas 10–14 mm; pollen sacs 0.5–0.7(–0.8) mm.
var. oreocharis
Source FNA vol. 17, p. 128. FNA vol. 17, p. 220.
Parent taxa Plantaginaceae > Penstemon > subg. Penstemon > sect. Cristati Plantaginaceae > Penstemon > subg. Penstemon > sect. Penstemon
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. 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. 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. rydbergii var. aggregatus, P. rydbergii var. oreocharis, P. rydbergii var. rydbergii
Name authority Nuttall: Gen. N. Amer. Pl. 2: 53. (1818) — (as Pentstemon albidum) A. Nelson: Bull. Torrey Bot. Club 25: 281. (1898) — (as Pentstemon)
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