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

toad-flax beardtongue, toadflax penstemon

Rocky Mountain beardtongue, Rocky Mountain penstemon

Stems

ascending to erect, 8–50 cm, retrorsely hairy, hairs pointed or white, scalelike.

ascending to erect, (20–)35–70(–90) cm, glabrous or ± puberulent proximally, rarely distinctly puberulent, not glaucous.

Leaves

not leathery, glabrous, glabrate, or sparsely to densely retrorsely hairy, hairs pointed, sometimes appressed, white, scalelike;

cauline 6–12(–20) pairs, petiolate or sessile, 4–26 × 0.5–3.5 mm, blade oblanceolate to lanceolate or linear, base tapered to truncate, apex mucronate.

basal and cauline, ± leathery or not, glabrous except for antrorsely-scabrous margins or ± puberulent proximally, rarely distinctly puberulent, not glaucous;

basal and proximal cauline (30–)50–150 × 5–16(–20) mm, blade oblanceolate, base tapered, margins entire, apex rounded to obtuse;

cauline 4–8 pairs, sessile, 40–100 × 2–7(–10) mm, blade lanceolate to linear, base tapered, apex acuminate.

Thyrses

continuous or interrupted, ± secund, 3–17 cm, axis glandular-pubescent, verticillasters 3–9(–12), cymes 1 or 2(or 3)-flowered, 1(or 2) per node;

proximal bracts lanceolate to linear, 6–25 × 0.7–1 mm;

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

interrupted to ± continuous, secund, (3–)9–40 cm, axis glabrous, verticillasters 4–10(–13), cymes 1- or 2(–4)-flowered, 2 per node;

proximal bracts lanceolate to linear, 10–65 × 1–8 mm, apex acuminate;

peduncles and pedicels glabrous, peduncles to 27 mm, pedicels 1–20 mm.

Flowers

calyx lobes ovate, rarely lanceolate, 4–7(–9) × 2–3 mm, broadly scarious-margined, apex acute to acuminate, glandular-pubescent, hairs pointed;

corolla blue or lavender, lined internally abaxially with reddish purple nectar guides, ventricose-ampliate, 16–20 mm, moderately white- or yellowish villous internally abaxially, tube 5–6 mm, throat abruptly inflated, 5.5–8 mm diam., slightly 2-ridged abaxially;

stamens: longer pair reaching orifice or slightly exserted, filaments glabrous, pollen sacs opposite, navicular, 0.9–1.3 mm, sutures papillate;

staminode 6–8 mm, exserted, flattened distally, 0.3–0.5 mm diam., tip straight to recurved, distal 1–5 mm densely pilose, hairs yellow or golden yellow, to 1.2 mm, rest of distal 1–7 mm glabrous or sparsely to moderately pilose;

style 10–11 mm.

calyx lobes ovate, (2.5–)3–5 × 1.3–2.5 mm, apex acute, sometimes acuminate or obtuse, glabrous;

corolla purple to violet or blue, with violet nectar guides, ventricose-ampliate, (18–)24–32 mm, glabrous externally, glabrous internally, tube 4–7 mm, throat gradually inflated, slightly constricted at orifice, 6–10(–12) mm diam., slightly 2-ridged abaxially;

stamens: longer pair slightly exserted, pollen sacs divergent to opposite, navicular-sigmoid, 1.7–2.4 mm, dehiscing incompletely, proximal 1/4 sometimes indehiscent, connective not splitting, sides moderately to densely lanate to villous, hairs white, to 1.8 mm, sutures denticulate, teeth to 0.1 mm;

staminode 11–14 mm, included, 0.5–0.8 mm diam., tip straight, glabrous or distal 1–5 mm sparsely villous, hairs yellow or orange, to 0.7 mm;

style 17–21 mm.

Capsules

5–9 × 3.5–5 mm.

7–13 × 4–7 mm.

2n

= 16.

Penstemon linarioides

Penstemon strictus

Phenology Flowering Jun–Aug.
Habitat Gravelly sagebrush shrublands, pinyon-juniper woodlands, oak woodlands, spruce-aspen forests.
Elevation 1700–3500 m. (5600–11500 ft.)
Distribution
from FNA
AZ; CO; NM; NV; UT
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CA; CO; NM; UT; WY
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 4 (4 in the flora).

Penstemon linarioides is widespread and highly variable. D. D. Keck (1937) recognized seven subspecies on the basis of habit, pubescence, leaf shape, and staminode bearding. Some of the variation on which those subspecies are based appears to be clinal or too variable within or among regional populations to be of taxonomic value.

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

A disjunct population of Penstemon strictus in Mono County, California, appears to be an introduction, and collections from some counties in east-central Colorado (Arapahoe) and northeastern New Mexico (Harding and Union) also probably are due to recent introductions. Penstemon strictus is a popular ornamental; it has been seeded along some highways in Arizona, Colorado, and Wyoming.

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

Key
1. Leaves glabrous, glabrate, retrorsely hairy, or pubescent, hairs pointed.
var. sileri
1. Leaves sparsely to densely retrorsely hairy, hairs appressed, white, scalelike.
→ 2
2. Cauline leaf blades oblanceolate, distals sometimes lanceolate, 1.5–3.5 mm wide.
var. maguirei
2. Cauline leaf blades oblanceolate to linear, 0.5–2 mm wide.
→ 3
3. Staminodes: distal 3–5 mm densely pilose, hairs golden yellow or yellow, to 1 mm, rest of distal 1–4 mm sparsely to moderately pilose.
var. linarioides
3. Staminodes: distal 1 mm densely pilose, hairs yellow, to 0.8 mm, rest of distal 3–4 mm glabrous or sparsely pilose (with much shorter hairs).
var. coloradoensis
Source FNA vol. 17, p. 103. FNA vol. 17, p. 180.
Parent taxa Plantaginaceae > Penstemon > subg. Penstemon > sect. Caespitosi Plantaginaceae > Penstemon > subg. Penstemon > sect. Glabri
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. 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. 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. 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. linarioides var. coloradoensis, P. linarioides var. linarioides, P. linarioides var. maguirei, P. linarioides var. sileri
Synonyms P. strictus subsp. angustus
Name authority A. Gray: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 112. (1859) — (as Pentstemon) Bentham: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 10: 324. (1846) — (as Pentstemon)
Web links