The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

mat beardtongue, mat penstemon

large beardtongue, largeflower penstemon, shell-leaf beardtongue

Stems

prostrate, only tip ascending, 2–8(–10) cm, not cinereous, retrorsely hairy, hairs pointed.

erect, (40–)50–95(–120) cm, glabrous.

Leaves

not leathery, not cinereous, retrorsely hairy, hairs pointed;

cauline 3–20 pairs, petiolate, 2.5–14(–21) × 1–4 mm, blade obovate to spatulate, oblanceolate, or linear, base tapered, apex rounded to acute or mucronate.

basal and cauline, glabrous;

basal and proximal cauline 30–160 × 6–50 mm, blade spatulate to obovate, base tapered, apex rounded to obtuse or acute;

cauline 4–8 pairs, sessile, 18–90(–110) × 15–50 mm, blade spatulate to orbiculate, base clasping, apex rounded to obtuse.

Thyrses

continuous, cylindric to secund, 0.5–3 cm, axis retrorsely hairy to retrorsely cinereous, hairs pointed, sometimes also glandular-pubescent, verticillasters 1–5, cymes 1–3-flowered, 1 per node;

proximal bracts linear, 2.8–13(–17) × 0.7–3 mm;

peduncles and pedicels ascending to erect, retrorsely hairy to retrorsely cinereous, hairs pointed, and glandular-pubescent.

interrupted, cylindric, 12–30(–40) cm, axis glabrous, verticillasters 3–7(–9), cymes 2–4-flowered;

proximal bracts ovate to elliptic or orbiculate, (9–)16–83 × (9–)16–54 mm;

peduncles and pedicels glabrous.

Flowers

calyx lobes lanceolate to linear, 4–6.5(–8.5) × 1–1.5(–1.9) mm, herbaceous- or narrowly scarious-margined, retrorsely hairy, hairs pointed, and sparsely glandular-pubescent;

corolla blue to purplish lavender or lavender, lined internally abaxially with reddish violet nectar guides, funnelform, 10–17(–21) mm, yellow-villous internally abaxially, tube 5–6 mm, throat gradually inflated, 4.5–6 mm diam., 2-ridged abaxially;

stamens: longer pair reaching orifice or exserted, filaments glabrous, pollen sacs opposite, navicular to explanate, 0.6–1.2 mm, sutures papillate;

staminode 9–12 mm, reaching orifice, flattened distally, 0.3–0.5 mm diam., tip straight to recurved, distal 7–9 mm densely pilose, hairs golden yellow, to 1 mm;

style 13–15 mm.

calyx lobes ovate to lanceolate, 7–11 × 2.5–4 mm, margins entire, rarely erose, herbaceous or narrowly scarious, glabrous;

corolla lavender to blue or pinkish blue, with magenta nectar guides, ampliate, 35–48 mm, glabrous externally, glabrous internally, tube 10–13 mm, throat abruptly inflated, 15–18 mm diam., rounded abaxially;

stamens included, pollen sacs opposite, 2.1–2.6 mm, sutures papillate;

staminode 16–21 mm, included or reaching orifice, 2–2.6 mm diam., tip recurved to coiled, distal 1–2 mm sparsely villous, hairs golden yellow, to 0.5 mm;

style 19–30 mm.

Capsules

3.5–5 × 3–4 mm.

16–20(–25) × 8–15 mm.

2n

= 16.

Penstemon caespitosus

Penstemon grandiflorus

Phenology Flowering Apr–Jul.
Habitat Sandy or calcareous soils, tallgrass, mixed-grass, and sand prairies.
Elevation 200–1800(–2400) m. (700–5900(–7900) ft.)
Distribution
from FNA
AZ; CO; UT; WY
[WildflowerSearch map]
[BONAP county map]
from FNA
CO; CT; IA; IL; IN; KS; MA; MI; MN; MO; MT; ND; NE; NM; OH; OK; SD; TX; WY
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 3 (3 in the flora).

The varieties of Penstemon caespitosus are weakly differentiated and largely allopatric.

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

Widely distributed in the western Midwest and Great Plains in the United States, Penstemon grandiflorus is cultivated as an ornamental for its showy flowers. Reports from Connecticut (D. W. Magee and H. E. Ahles 2007), Indiana (K. Yatskievych 2000), Massachusetts (Magee and Ahles), Michigan (E. G. Voss 1972–1996), and Ohio (T. S. Cooperrider 1995) appear to be based on introductions. Penstemon grandiflorus has been seeded along highways in Iowa and Nebraska, where it is also native.

The validity of the name Penstemon grandiflorus has been debated owing to the meager diagnosis by Nuttall. The name is accepted here, making P. bradburyi Pursh, an illegitimate, superfluous replacement for P. grandiflorus.

The Dakota, Kiowa, and Sioux tribes, centered in the Great Plains, use Penstemon grandiflorus as an analgesic, a gastrointestinal aid, and for fevers (D. E. Moerman 1998).

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

Key
1. Pollen sacs 0.9–1.2 mm; leaf blades oblanceolate; Arizona, Utah.
var. desertipicti
1. Pollen sacs 0.6–0.9 mm; leaf blades obovate, spatulate, oblanceolate, or linear; Colorado, Utah, Wyoming.
→ 2
2. Leaf blades oblanceolate to linear; pollen sacs explanate, 0.6–0.8 mm; Colorado, Utah, Wyoming.
var. caespitosus
2. Leaf blades obovate or spatulate; pollen sacs navicular to subexplanate, 0.8–0.9 mm; Colorado, Utah.
var. perbrevis
Source FNA vol. 17, p. 100. FNA vol. 17, p. 118.
Parent taxa Plantaginaceae > Penstemon > subg. Penstemon > sect. Caespitosi Plantaginaceae > Penstemon > subg. Penstemon > sect. Coerulei
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. 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. 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. caespitosus var. caespitosus, P. caespitosus var. desertipicti, P. caespitosus var. perbrevis
Name authority Nuttall ex A. Gray: Proc. Amer. Acad. Arts 6: 66. (1862) — (as Pentstemon) Nuttall: Cat. Pl. Upper Louisiana, no. 64. (1813) — (as grandiflorum)
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