Penstemon humilis var. humilis
Penstemon sect. Penstemon
low beardtongue, lowly penstemon
glabrous, glabrate, retrorsely hairy, puberulent, or pubescent, sometimes glandular-pubescent, glandular-lanate, or glandular-villous, rarely glutinous, glaucous or not.
basal leaves puberulent or retrorsely hairy, (8–)15–105 × 2–13(–18) mm, cauline blade margins entire, rarely ± serrate distally.
basal and cauline, sometimes basals absent or poorly developed, opposite, rarely whorled (P. deustus), subopposite (P. deustus, P. sudans), or alternate (P. gairdneri, P. seorsus), leathery or not, glabrous, glandular, puberulent, glandular-pubescent, glandular-lanate, retrorsely hairy, pubescent, or glabrate, not glaucous or rarely so (P. euglaucus, P. glaucinus), sometimes ± glaucescent (P. albomarginatus, P. griffinii, P. inflatus, P. oliganthus, P. tracyi);
basal and proximal cauline petiolate;
cauline sessile or petiolate, blade obovate, ovate, triangular-ovate, spatulate, oblanceolate, lanceolate, oblong, elliptic, or linear, rarely lyrate, margins entire or toothed.
continuous or interrupted, cylindric to conic, rarely secund, axis glabrous or glandular-pubescent, puberulent, pubescent, or retrorsely hairy, rarely glandular-lanate, cymes 1 or 2 per node;
peduncles and pedicels spreading to ascending or erect.
corolla (7–)12–19 mm.
calyx lobes: margins entire, erose, or lacerate, ± scarious, sometimes herbaceous, glandular-pubescent or glabrous, rarely glabrescent, puberulent, retrorsely hairy, glutinous, or glandular-ciliolate;
corolla white, ochroleucous, pink, lavender, blue, violet, purple, or yellow, bilaterally symmetric, bilabiate or strongly bilabiate, rarely weakly bilabiate (P. tubaeflorus), not personate, sometimes personate (P. hirsutus, P. oklahomensis, P. tenuiflorus) or nearly personate (P. australis, P. degeneri, P. griffinii, P. laxiflorus, P. oliganthus), funnelform, tubular-funnelform, tubular, ampliate, or ventricose, glabrous, glabrate, glabrescent, or glandular-pubescent externally, glabrous or hairy internally abaxially, rarely glandular-pubescent abaxially and adaxially, throat slightly to abruptly inflated to slightly ventricose, not constricted at orifice, slightly to prominently 2-ridged adaxially, rarely rounded;
stamens included or longer pair reaching orifice or exserted, filaments glabrous, pollen sacs opposite or divergent, rarely parallel, navicular to subexplanate or explanate, rarely saccate, dehiscing completely, rarely incompletely, distal 1/5–2/3 sometimes indehiscent, connective splitting, rarely not, sides glabrous, rarely hairy, sutures papillate, sometimes smooth;
staminode included to exserted, flattened distally, 0.2–0.8(–1.1) mm diam., tip straight to recurved, distal 5–60(–90)% hairy, hairs to 3 mm, sometimes glabrous;
style glabrous.
glabrous, rarely glandular-puberulent distally.
tan, brown, gray, or black, angled to slightly rounded, 0.4–2(–3.5) mm.
= 16.
Penstemon humilis var. humilis
Penstemon sect. Penstemon
CA; CO; ID; MT; NV; OR; UT; WA; WY
North America
Welsh described var. desereticus based on material with relatively larger corollas (15–19 mm) and smaller basal leaves (8–25 × 2–6 mm) from mountain ranges in the western Bonneville Basin of Utah; E. C. Neese and N. D. Atwood (2003) considered the variety to be limited to Utah. Variety desereticus appears to be confluent with a form of the species in the Calcareous Mountains of eastern Nevada, which N. H. Holmgren (1984) discussed and later recognized as Penstemon decurvus (Holmgren 2017). Penstemon decurvus, described from eastern Lincoln County, Nevada, also is referable here. Plants from northeastern California, extreme southwestern Idaho, extreme northwestern Nevada, and eastern and central Oregon often have cinereous leaves and relatively longer stems, shorter calyx lobes, and, sometimes, more open inflorescences; these plants have been called P. cinereus. This element grades into other phases to the east and appears to be another form of highly variable var. humilis. Some specimens from eastern Idaho (Clark and Fremont counties) have glabrous leaves, possibly from genetic exchange with P. aridus.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Species 62 (62 in the flora).
Elaborate subsectional classifications were presented by D. D. Keck (1945) and F. S. Crosswhite (1965b). Those are not followed; a more well-resolved phylogeny of the genus is needed.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
0. Penstemon East of the Rocky Mountains. | → 1 |
1. Pollen sacs parallel, saccate, dehiscing incompletely. | P. multiflorus |
1. Pollen sacs opposite or divergent, navicular, subexplanate, or explanate, dehiscing completely. | → 2 |
2. Corollas glabrous externally. | P. procerus |
2. Corollas glandular-pubescent externally. | → 3 |
3. Corollas glandular-pubescent internally, without nectar guides; pollen sacs explanate. | P. tubaeflorus |
3. Corollas hairy internally, not glandular-pubescent, with, sometimes without, nectar guides; pollen sacs navicular or subexplanate. | → 4 |
4. Corollas personate, with or without nectar guides. | → 5 |
5. Corollas lavender or purplish; leaves glabrous or sparsely glandular-lanate along midveins, rarely moderately glandular-lanate. | P. hirsutus |
5. Corollas white to ochroleucous; leaves puberulent or retrorsely hairy, or moderately to densely glandular-lanate, especially along major veins abaxially. | → 6 |
6. Leaves puberulent or retrorsely hairy; cauline leaf blades lanceolate to linear; Oklahoma, Texas. | P. oklahomensis |
6. Leaves moderately to densely glandular-lanate, especially along major veins abaxially; cauline leaf blades ovate to lanceolate; Alabama, Kentucky, Mississippi, Tennessee. | P. tenuiflorus |
4. Corollas not personate, sometimes nearly personate, with nectar guides. | → 7 |
7. Stems glabrous or glabrate, puberulent, or retrorsely hairy. | → 8 |
8. Corollas tubular to tubular-funnelform. | → 9 |
9. Cauline leaf pairs (6–)8–12; corollas 15–19 mm; capsules 4–7 mm. | P. arkansanus |
9. Cauline leaf pairs (3–)5–7; corollas 20–28(–30) mm; capsules 8–10 mm. | P. laxiflorus |
8. Corollas ventricose, sometimes funnelform. | → 10 |
10. Corollas (17–)20–35 mm; calyx lobes 4–9 mm. | → 11 |
11. Pollen sac sides glabrous, rarely sparsely pubescent; calyx lobes 5–9 × 0.8–1.9 mm, apices acuminate; corollas pale lavender to violet. | P. calycosus |
11. Pollen sac sides sparsely pubescent, rarely glabrous; calyx lobes 4–8 × 2–3 mm, apices acute to acuminate; corollas white, sometimes tinged lavender. | P. digitalis |
10. Corollas 10–22 mm; calyx lobes 1.5–6 mm. | → 12 |
12. Corollas 10–14 mm, funnelform; cauline leaf margins sharply serrate, sometimes ± serrate. | P. tenuis |
12. Corollas 15–22 mm, ventricose; cauline leaf margins entire or denticulate, serrulate, or ± serrate. | → 13 |
13. Calyx lobes 1.5–3.5(–4) mm; corollas white. | P. deamii |
13. Calyx lobes 3–6 mm; corollas pale lavender to violet. | P. laevigatus |
7. Stems retrorsely hairy and glandular-pubescent, glandular-lanate, or glandular-villous, sometimes sparsely and only distally. | → 14 |
14. Corollas 28–35 mm; staminodes: distal 13–15 mm ± pilose; proximal bracts 56–130 × 23–55 mm, margins sharply serrate. | P. smallii |
14. Corollas 10–30 mm; staminodes: distal 4–12 mm hairy; proximal bracts 3–95 × 1–45 mm, margins entire, ± dentate, ± crenate, serrulate, or serrate. | → 15 |
15. Corollas ventricose. | P. canescens |
15. Corollas tubular to tubular-funnelform. | → 16 |
16. Corollas 20–28(–30) mm; styles 10–20 mm; capsules 6–10 mm. | → 17 |
17. Stems retrorsely hairy and glandular-lanate, glandular hairs sometimes sparse; cymes each usually with only 1 branch elongating, other branches distinctly shorter. | P. australis |
17. Stems puberulent to retrorsely hairy, rarely also glandular-pubescent distally; cymes each usually with all branches elongating and of equal length. | P. laxiflorus |
16. Corollas 10–24 mm; styles 9–17 mm; capsules 4–8 mm. | → 18 |
18. Corollas light lavender to lavender or purple; calyx lobes (1.5–)2–6 mm. | → 19 |
19. Calyx lobes (1.5–)2–3.5 mm; cauline leaves 11–32 mm wide, blades ovate to lanceolate or oblanceolate. | P. brevisepalus |
19. Calyx lobes 4–6 mm; cauline leaves (2–)4–10(–15) mm wide, blades lanceolate to linear. | P. gracilis |
18. Corollas white, sometimes tinged lavender or blue; calyx lobes (2–)2.8–5.5 mm. | → 20 |
20. Corollas 10–16 mm; cauline leaves 120–150 × 30–40 mm. | P. kralii |
20. Corollas 15–22 mm; cauline leaves 22–100 × 4–24 mm. | → 21 |
21. Stems retrorsely hairy, sometimes also ± glandular-pubescent distally; leaves glabrous or sparsely retrorsely hairy, especially along midveins and margins abaxially, glabrous or sparsely puberulent adaxially; cauline leaves (6–)8–12 pairs, blades lanceolate. | P. arkansanus |
21. Stems retrorsely hairy and glandular-villous proximally, retrorsely hairy and glandular-pubescent distally, glandular hairs sometimes sparse; leaves sparsely to densely pubescent, sometimes also with scattered glandular hairs abaxially, sparsely pubescent adaxially; cauline leaves 4–8 pairs, blades ovate to lanceolate. | P. pallidus |
0. Penstemon from the Rocky Mountains Westward. | → 1 |
1. Subshrubs; leaves alternate, subopposite, whorled, or opposite. | → 2 |
2. Leaves: margins dentate, dentate-serrate, serrate, or serrulate. | → 3 |
3. Thyrse axes, peduncles, pedicels, and calyx lobes ± glandular-pubescent. | P. deustus |
3. Thyrse axes, peduncles, pedicels, and calyx lobes densely glandular-pubescent. | P. sudans |
2. Leaves: margins entire. | → 4 |
4. Corollas white to ochroleucous, sometimes tinged lavender (abaxial lobes sometimes brown). | P. deustus |
4. Corollas blue to violet or purple. | → 5 |
5. Corollas glandular-pubescent internally. | P. gairdneri |
5. Corollas glabrous internally. | P. seorsus |
1. Herbs; leaves opposite. | → 6 |
6. Corollas glabrous externally; calyx lobes glabrous, rarely puberulent, retrorsely hairy, glandular-pubescent, or glandular-ciliolate. | → 7 |
7. Corollas yellow or light yellow. | → 8 |
8. Corollas 6–11 mm; pollen sacs 0.4–0.5 mm; staminodes 0.3–0.4 mm diam., distal 0.5–1 mm pilose. | P. confertus |
8. Corollas 12–16 mm; pollen sacs 0.7–0.9 mm; staminodes 0.4–0.7 mm diam., distal 2–3 mm moderately pilose. | P. flavescens |
7. Corollas white, ochroleucous, pink, pinkish lavender, lavender, blue, violet, or purple. | → 9 |
9. Pollen sacs dehiscing incompletely, distal 1/5–1/4 indehiscent. | P. globosus |
9. Pollen sacs dehiscing completely. | → 10 |
10. Staminodes glabrous. | → 11 |
11. Proximal bracts oval to oblong; corollas pinkish lavender, 13–18 mm. | P. albomarginatus |
11. Proximal bracts lanceolate to linear; corollas violet, blue, purple, lavender, or white, 7–15 mm. | → 12 |
12. Corollas white or lavender. | P. pratensis |
12. Corollas violet to blue or purple. | P. procerus |
10. Staminodes hairy. | → [13 |
13. Stems glabrous, glutinous, usually covered with sand; caudices rhizomelike. | P. arenarius |
13. Stems glabrous, retrorsely hairy, or puberulent, not glutinous and covered with sand; caudices not rhizomelike. | → 14 |
14. Stems and leaves glaucous. | P. euglaucus |
14. Stems and leaves not glaucous, rarely glaucescent. | → 15 |
15. Proximal bracts elliptic to ovate; thyrses 2–4 cm; stems 8–12 cm. | P. tracyi |
15. Proximal bracts lanceolate to linear, rarely ovate; thyrses 0.5–23(–50) cm; stems 3–70(–120) cm. | → 16 |
16. Calyx lobes 1–1.8 mm, apices truncate to cuspidate; corollas 7–9(–11) mm. | P. cinicola |
16. Calyx lobes 1.2–8 mm, apices truncate to obtuse, acute, short- to long-caudate, short- to long-cuspidate, acuminate, or mucronate; corollas 6–20 mm. | → 17 |
17. Leaves essentially cauline, basal absent or poorly developed. | → 18 |
18. Corollas densely yellow-villous internally abaxially; pollen sacs explanate; stems ± retrorsely hairy. | P. laxus |
18. Corollas sparsely white-villous internally abaxially; pollen sacs navicular; stems glabrous or sparsely puberulent. | P. watsonii |
17. Leaves basal and cauline, basal sometimes poorly developed. | → 19 |
19. Corollas yellow, white, ochroleucous, pink, or lavender; calyx lobes glabrous. | → 20 |
20. Pollen sacs explanate, 0.4–0.5 mm; corollas 6–11 mm. | P. confertus |
20. Pollen sacs navicular, 0.6–0.8 mm; corollas 10–15 mm. | P. pratensis |
19. Corollas violet to blue or purple; calyx lobes glabrous, retrorsely hairy, or puberulent. | → 21 |
21. Corollas 7–11 mm, throats 2–3 mm diam.; pollen sacs explanate, 0.3–0.6 mm. | P. procerus |
21. Corollas 10–20 mm, throats 3–4.5 mm diam.; pollen sacs navicular, 0.5–1.1 mm. | P. rydbergii |
6. Corollas glandular-pubescent externally, rarely glabrescent; calyx lobes glandular-pubescent, rarely glabrous or glabrescent. | → 22 |
22. Pollen sac sides sparsely puberulent. | P. bleaklyi |
22. Pollen sac sides glabrous. | → 23 |
23. Capsules glandular-pubescent distally. | P. whippleanus |
23. Capsules glabrous. | → 24 |
24. Thyrses ± conic, interrupted; peduncles and pedicels spreading to ascending or erect. | → 25 |
25. Cauline leaf blades oblanceolate to lanceolate or linear, rarely ovate, margins entire; staminodes: distal 6–10 mm pilose. | → 26 |
26. Pollen sacs 0.9–1.1 mm; corollas 14–19 mm; Colorado. | P. degeneri |
26. Pollen sacs 1.3–1.6 mm; corollas 17–27 mm; New Mexico. | P. inflatus |
25. Cauline leaf blades oblong to ovate, triangular-ovate, or lanceolate, margins serrulate, serrate, or dentate, sometimes entire; staminodes: distal 1–5 mm pilose to villous. | → 27 |
27. Thyrse axes sparsely to moderately glandular-pubescent; calyx lobes ovate, margins broadly scarious. | P. wilcoxii |
27. Thyrse axes moderately to densely glandular-pubescent; calyx lobes ovate to lanceolate, margins narrowly to broadly scarious. | → 28 |
28. Corollas 15–22 mm; staminodes: distal 1–2 mm densely pilose, hairs yellow; cauline leaf blades oblong to ovate or triangular-ovate. | P. ovatus |
28. Corollas 12–18 mm; staminodes: distal 2–3 mm sparsely to moderately pilose, hairs yellow or yellow-orange; cauline leaf blades lanceolate to oblong. | P. subserratus |
24. Thyrses cylindric or secund, continuous or interrupted; peduncles and pedicels ascending to erect. | → 29 |
29. Stems and leaves glaucous; corollas without nectar guides. | P. glaucinus |
29. Stems and leaves not glaucous, leaves rarely ± glaucescent (P. griffinii, P. oliganthus); corollas with, sometimes without, nectar guides. | → 30 |
30. Caudices rhizomelike; leaves cauline; alpine talus, gravel slopes, boulder fields, 3200–4200 m. | P. harbourii |
30. Caudices not rhizomelike; leaves basal and cauline, basal sometimes poorly developed, rarely absent; prairies, meadows, woodlands, forests, 30–3900 m. | → 31 |
31. Staminodes exserted; corollas ventricose, ventricose-ampliate, or ampliate. | → 32 |
32. Corollas 13–18 mm; styles 10–13 mm; staminodes: distal 2–6 mm sparsely pilose, hairs yellow, to 0.6 mm, rarely glabrous; pollen sacs 0.8–1.2 mm. | P. anguineus |
32. Corollas 20–30 mm; styles 16–19 mm; staminodes: distal 6–10 mm sparsely to moderately lanate, hairs yellow or white, to 3 mm; pollen sacs 1.2–1.5 mm. | P. rattanii |
31. Staminodes included or reaching orifices, rarely slightly exserted; corollas tubular, tubular-funnelform, or funnelform. | → 33 |
33. Proximal cauline leaves 1–5(–7) mm wide, blades linear to narrowly elliptic or narrowly oblanceolate, margins entire. | → 34 |
34. Calyx lobes ovate to lanceolate, 2.2–4.6 × 1–2.4 mm; stems 6–20(–25) cm; corollas 11–17 mm, blue to violet. | P. aridus |
34. Calyx lobes obovate to ovate or lanceolate, 1.5–3 × 0.7–1.5 mm; stems 20–50(–65) cm; corollas 8–10 mm, violet to light blue, pink, or light purple. | P. peckii |
33. Proximal cauline leaves 2–55 mm wide, blades triangular to ovate, lanceolate, oblanceolate, elliptic, obovate, or spatulate, margins serrate, dentate, serrulate, denticulate, or entire. | → 35 |
35. Leaves essentially cauline, basal absent or poorly developed; cauline leaf blade margins entire. | P. radicosus |
35. Leaves basal and cauline; cauline leaf blade margins serrate, dentate, serrulate, denticulate, or entire. | → 36 |
36. Caudices herbaceous; corollas tubular. | P. gracilis |
36. Caudices not herbaceous; corollas tubular, tubular-funnelform or funnelform. | → 37 |
37. Thyrses secund; proximal bracts lanceolate to linear. | → 38 |
38. Cauline leaf blades linear; corollas densely golden-villous internally abaxially, hairs passing onto limbs (and deep into throats), 17–25 mm; Colorado, New Mexico. | P. griffinii |
38. Cauline leaf blades oblanceolate to lanceolate; corollas sparsely to moderately white-villous to white-lanate internally abaxially, 11–20 mm; Arizona, New Mexico. | P. oliganthus |
37. Thyrses cylindric to conic, rarely ± secund; proximal bracts ovate to lanceolate. | → 39 |
39. Corollas light yellow; leaves glabrous. | P. flavescens |
39. Corollas blue, lavender, violet, bluish purple, or purple, rarely light yellow or whitish; leaves glabrous or puberulent to retrorsely hairy, pubescent, or glandular-pubescent. | → 40 |
40. Corollas 9–12 mm, throats 2–3 mm diam.; pollen sacs 0.5–0.6 mm; thyrses 1–6 cm; Washington. | P. washingtonensis |
40. Corollas (7–)8–23 mm, throats 3–9 mm diam.; pollen sacs 0.5–1.2 mm; thyrses 1–39 cm; widespread, including Washington. | → 41 |
41. Stems and leaves glaucous. | P. glaucinus |
41. Stems and leaves not glaucous. | → 42 |
42. Basal and proximal cauline leaf blades triangular to ovate or lanceolate; peduncles and pedicels spreading to ascending; corolla throats 4–9 mm diam. | P. wilcoxii |
42. Basal and proximal cauline leaf blades ovate to obovate, lanceolate, oblanceolate, elliptic, or spatulate; peduncles and pedicels ascending to erect; corolla throats 3–6 mm diam. | → 43 |
43. Staminodes: distal 4–6 mm villous or pilose. | → 44 |
44. Pollen sacs 0.9–1.2 mm; cauline leaves 12–27 mm wide; peduncles and pedicels erect; corollas 16–20 mm, tube 5–7 mm; calyx lobes lanceolate. | P. metcalfei |
44. Pollen sacs 0.5–0.8 mm; cauline leaves 1–14 mm wide; peduncles and pedicels ascending to erect; corollas (7–)8–19 mm, tube 2–5 mm; calyx lobes ovate to lanceolate. | → 45 |
45. Leaves glabrous, retrorsely hairy, or puberulent, blade margins entire, sometimes serrulate or serrate; California, Colorado, Idaho, Montana, Nevada, Oregon, Utah, Washington, Wyoming. | P. humilis |
45. Leaves glabrous, blade margins serrulate or denticulate, sometimes entire; Colorado, Wyoming. | P. virens |
43. Staminodes: distal 0.5–4 mm villous or pilose. | → 46 |
46. Corollas essentially without nectar guides; leaves glabrous; blade margins entire. | P. heterodoxus |
46. Corollas with nectar guides; leaves retrorsely hairy, puberulent, or glabrous; blade margins ± serrulate, serrate, dentate, denticulate, or entire. | → 47 |
47. Staminodes 9–12 mm; corollas 14–23 mm, throats 5–6 mm diam. | P. elegantulus |
47. Staminodes (3–)6–10 mm; corollas 7–20 mm, throats 3–6 mm diam. | → 48 |
48. Cauline leaf blade margins serrulate to serrate or dentate, sometimes entire; proximal bract margins serrate to serrulate, sometimes entire; cymes 3–11-flowered. | → 49 |
49. Pollen sacs 0.6–0.8 mm; staminodes: distal 0.5–1 mm densely pilose, hairs yellow, to 0.8 mm; basal and cauline leaves retrorsely hairy or pubescent, sometimes also glandular-pubescent; cauline leaf blades triangular-ovate to lanceolate. | P. pruinosus |
49. Pollen sacs 0.7–1.1 mm; staminodes: distal 2–3 mm sparsely to moderately pilose, hairs yellow or yellow-orange, to 1.5 mm; basal and cauline leaves glabrous or puberulent; cauline leaf blades lanceolate to oblong. | P. subserratus |
48. Cauline leaf blade margins entire, sometimes ± serrulate, or dentate, rarely ± serrate; proximal bract margins entire or ± serrate to dentate; cymes (1–)2–8(–11)-flowered. | → 50 |
50. Pollen sacs saccate, dehiscing incompletely, distal 1/5 or less sometimes indehiscent. | P. attenuatus |
50. Pollen sacs navicular, subexplanate, or explanate, dehiscing completely. | → 51 |
51. Staminodes 9–12 mm; pollen sacs 0.9–1.2 mm; corollas 14–23 mm. | P. elegantulus |
51. Staminodes (3–)6–9 mm; pollen sacs 0.5–1.2 mm; corollas 7–20 mm. | → 52 |
52. Basal and proximal cauline leaf margins ± serrate or dentate; pollen sacs subexplanate to explanate. | P. albertinus |
52. Basal and proximal cauline leaf margins entire, sometimes denticulate, serrate, or serrulate; pollen sacs navicular to subexplanate. | → 53 |
53. Cauline leaves 1–3 pairs, sessile, bases truncate; proximal bracts 2–7 mm wide; staminodes: distal 0.5–1.5 mm densely pilose, hairs to 0.7 mm. | P. spatulatus |
53. Cauline leaves (1–)2–5(–7) pairs, sessile or proximals short- to long-petiolate, bases tapered to clasping; proximal bracts 1–15(–28) mm wide; staminodes: distal 1–4 mm sparsely to densely pilose, hairs to 1.2 mm. | → 54 |
54. Stems glabrous or retrorsely hairy; cauline leaves 2–25(–38) mm wide; peduncles and pedicels erect; calyx lobe margins erose to lacerate, apices acuminate to short-caudate or long-acuminate; pollen sacs 0.6–1.2 mm; staminodes 0.3–0.4 mm diam. | P. attenuatus |
54. Stems retrorsely hairy; cauline leaves 1–11 mm wide; peduncles and pedicels ascending to erect; calyx lobe margins entire or erose, apices acute; pollen sacs 0.5–0.8 mm; staminodes 0.1–0.3 mm diam. | P. humilis |
CA
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PNW Herbaria
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