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larch-leaf beardtongue

slender beardtongue, slender penstemon

Habit Plants cespitose. Subshrubs.
Stems

erect, 10–30 cm, glabrous or puberulent.

ascending to erect, 20–65 cm, glabrous or retrorsely hairy, hairs ± pointed, sometimes glaucous.

Leaves

basal and cauline, not leathery, glabrous, rarely puberulent proximally, especially along margins;

basal and proximal cauline sessile, 15–20(–40) × 0.5–1.5 mm, blade linear, base tapered to ± clasping, margins entire, apex acute;

cauline 3–7 pairs, sessile, 11–35 × 0.3–1 mm, blade linear, base tapered to ± clasping, margins entire, apex acute.

essentially cauline, basal absent or essentially so, opposite, glabrous, sometimes glaucous distally or abaxially;

cauline (3–)6–10 pairs, petiolate or sessile, (20–)40–80(–105) × (2–)4–15 mm, blade spatulate to oblanceolate or lanceolate, base tapered, margins entire, apex rounded to obtuse or acute.

Thyrses

continuous or interrupted, cylindric, 3–15 cm, axis glabrous or retrorsely hairy, verticillasters 3–7, cymes 1- or 2(or 3)-flowered, 1 or 2 per node;

proximal bracts linear, 10–30 × 0.3–1 mm;

peduncles and pedicels glabrous, rarely puberulent.

interrupted, cylindric, (3–)7–28 cm, axis glandular-pubescent, usually sparsely so proximally, verticillasters 3–6(–9), cymes 2–4(–7)-flowered, 2 per node;

proximal bracts lanceolate to linear, 14–75 × 1–6 mm;

peduncles and pedicels ascending to erect, glandular-pubescent.

Flowers

calyx lobes ovate, 3.5–5.8 × 1.3–2.2 mm, glabrous;

corolla white or pink to violet or purple, without nectar guides, tubular-funnelform, 9–18 mm, glabrous externally, moderately yellow-villous internally abaxially, tube 4–5 mm, throat gradually inflated, not constricted, 5–6 mm diam., rounded abaxially;

stamens included, pollen sacs opposite, navicular, 1–1.5 mm, dehiscing completely, sutures papillate;

staminode 7–11 mm, included or reaching orifice, 0.5–0.7 mm diam., tip straight to recurved, distal 3–5 mm pilose, hairs yellow or yellow-orange, to 1 mm;

style 9–12 mm.

calyx lobes oblong to lanceolate, 3.5–5.5 × 0.8–1.4 mm, glandular-pubescent;

corolla blue to violet or purple, with or without dark blue nectar guides, funnelform, 15–20(–24) mm, glandular-pubescent externally, glabrous internally or sparsely to densely white- or yellow-pilose abaxially, tube 6–8 mm, throat gradually inflated, 4–5 mm diam., 2-ridged abaxially;

stamens included or longer pair reaching orifice, filaments glabrous, pollen sacs parallel, 1–1.3 mm, distal 1/2 indehiscent, sides glabrous, sutures denticulate, teeth to 0.1 mm;

staminode 8–10 mm, included, 0.3–0.4 mm diam., distal 3–5 mm sparsely to moderately pubescent, hairs yellow, to 0.5 mm;

style 12–15 mm.

Capsules

4–5 × 2.5–4 mm.

5–7 × 3.5–4 mm.

2n

= 16.

Penstemon laricifolius

Penstemon gracilentus

Phenology Flowering Jun–Aug.
Habitat Lava and granitic sand or gravel, sagebrush shrublands, juniper woodlands, pine-fir forests.
Elevation 1000–3000 m. (3300–9800 ft.)
Distribution
from FNA
CO; MT; WY
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; NV; OR
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 2 (2 in the flora).

Molecular data (A. D. Wolfe et al. 2006; C. A. Wessinger et al. 2016) place Penstemon laricifolius with or near sect. Cristati. Two varieties, differentiated by corolla color, are difficult to distinguish in the herbarium, where corollas are usually brown. Populations with a mix of white, pink, and purple corollas have been documented in Wyoming (B. L. Heidel and J. Handley 2007).

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

Penstemon gracilentus occurs from south-central Oregon (Lake County) through northeastern California and northwestern Nevada to near Lake Tahoe. D. D. Keck (1932) hypothesized that P. gracilentus was closely related to species of sect. Penstemon; his hypothesis is supported by molecular data (A. D. Wolfe et al. 2006).

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

Key
1. Corollas pink to violet or purple, 10–18 mm; Montana, Wyoming.
var. laricifolius
1. Corollas white, 9–15 mm; Colorado, Wyoming.
var. exilifolius
Source FNA vol. 17, p. 138. FNA vol. 17, p. 234.
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. 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. 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. 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. laricifolius var. exilifolius, P. laricifolius var. laricifolius
Name authority Hooker & Arnott: Bot. Beechey Voy., 376. (1839) — (as Pentstemon) A. Gray: in War Department [U.S.], Pacif. Railr. Rep. 6(3): 82. (1858) — (as Pentstemon)
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