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Thurber's beardtongue, Thurber's penstemon

cobaea beardtongue, cobaea penstemon

Stems

20–40 cm, glabrous or glabrate.

retrorsely ascending to erect, (15–)25–65(–100) cm, puberulent proximally, glandular-pubescent distally.

Leaves

10–20 pairs, 5–32 × 0.3–2 mm, blade base tapered, margins glabrous or scabrous, apex acuminate to mucronate.

basal and cauline, sometimes basal absent or withering, ± leathery or not, glabrous or puberulent to pubescent;

basal and proximal cauline petiolate, 35–120(–150) × 8–55(–76) mm, blade spatulate to oblanceolate or elliptic, base tapered, margins subentire or serrate to dentate, apex rounded to acute;

cauline 4–8 pairs, sessile, 35–120(–150) × 10–45(–54) mm, blade ovate to lanceolate, base tapered to cordate-clasping, margins subentire to serrate or dentate, apex acute, rarely obtuse.

Thyrses

2–15(–23) cm, verticillasters (2–)5–10(–30), cymes 1- or 2-flowered;

proximal bracts linear, 3–22 × 0.2–1 mm;

peduncles and pedicels glabrous or scabrous.

interrupted or continuous, cylindric, 10–30(–52) cm, axis densely glandular-pubescent, verticillasters 3–6(–8), cymes 2–6-flowered, 2 per node;

proximal bracts ovate, 20–78 × 8–74 mm;

peduncles and pedicels densely glandular-pubescent.

Flowers

calyx lobes ovate, 1–2.7 × 0.9–1.5 mm;

corolla lavender to violet, lined internally abaxially with reddish purple nectar guides, funnelform, 8–14 mm, glandular-pubescent internally in 2 lines on abaxial surface, sometimes also in sinuses of adaxial lobes, tube (1.5–)2–3 mm, throat 3–5 mm diam.;

stamens included or longer pair reaching orifice or barely exserted, pollen sacs 0.4–0.5 mm;

staminode 5–6 mm;

style 7–9 mm.

calyx lobes ovate to lanceolate, (8–)10–16 × 2.5–4.5 mm, densely glandular-pubescent;

corolla white to pink or violet to purple, with reddish purple nectar guides, ventricose-ampliate, 35–55 mm, glandular-pubescent internally, tube 10–14 mm, throat abruptly inflated, slightly constricted at orifice, (15–)18–25 mm diam., rounded abaxially;

stamens included, pollen sacs opposite, explanate, 1.3–1.6 mm, dehiscing completely, sutures smooth;

staminode 23–30 mm, included or barely exserted, 0.6–0.9 mm diam., tip recurved, distal 20–25 mm sparsely to moderately villous, hairs white or golden yellow, to 3.5 mm;

style 18–34 mm.

Capsules

(4–)5–8 × 3–4 mm.

13–18 × 8–10 mm.

2n

= 16.

Penstemon thurberi

Penstemon cobaea

Phenology Flowering Apr–Aug(–Sep).
Habitat Sandy or rocky slopes, chaparral, creosote shrublands, pine-juniper woodlands.
Elevation 500–1200(–2100) m. (1600–3900(–6900) ft.)
Distribution
from FNA
AZ; CA; NM; NV; TX; UT; Mexico (Baja California, Chihuahua)
[WildflowerSearch map]
[BONAP county map]
from FNA
AR; AZ; CO; IA; IL; KS; MO; NE; NM; OH; OK; TX
[WildflowerSearch map]
[BONAP county map]
Discussion

Plants of Penstemon thurberi from northern Clark County, Nevada, with corollas 8–9 mm and capsules 4–5 mm have been treated as var. anestius.

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

Varieties 2 (2 in the flora).

Penstemon cobaea occurs widely in the central and southern Great Plains and into the Ozark Plateau. The species is a popular ornamental used in the breeding of the European or large-flowered hybrids of Penstemon (D. Lindgren and E. Wilde 2003). A chromosome count of n = 32 (R. Piotrowska 1934) appears doubtful.

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

Key
1. Corollas white to pink.
var. cobaea
1. Corollas violet to purple.
var. purpureus
Source FNA vol. 17, p. 95. FNA vol. 17, p. 131.
Parent taxa Plantaginaceae > Penstemon > subg. Penstemon > sect. Ambigui Plantaginaceae > Penstemon > subg. Penstemon > sect. Cristati
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. 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. 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. 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
Subordinate taxa
P. cobaea var. cobaea, P. cobaea var. purpureus
Synonyms P. thurberi var. anestius
Name authority Torrey: Pacif. Railr. Rep. Parke, Bot., 15. (1856) — (as Pentstemon) Nuttall: Trans. Amer. Philos. Soc., n. s. 5: 182. (1835) — (as Pentstemon)
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