Home › P › Pentstemon (From pente five and stemon)

Pentstemon (From pente five and stemon)

(from pente, five, and stemon, a stamen; the fifth stamen being present and conspicuous, although sterile). Beard-tongue. SYN. Penstemon. ORD. Scrophularineae. A genus comprising about sixty-six species of very ornamental, mostly hardy, perennial herbs or sub-shrubs, natives of (mostly Western) North America, including Mexico. Flowers red, violet, blue, white, or rarely yellowish-white, showy; calyx of five imbricated segments; corolla tube usually elongated, equal or ventricose; limb bilabiate, the upper lip two-lobed, and the lower three-cleft, bearded or naked; stamens four, didynamous, shorter than the corolla, the staminode filiform, with a clavate or spathulate tip, generally much shorter than the stamens; peduncles dichotomously many-flowered, bracteate at the ramifications and disposed in a terminal panicle or thyrse, which is often leafy at base, rarely one-flowered, and disposed in a simple raceme. Leaves opposite, the radical and lower ones petioled, graduating into amplexicaul floral ones, or decreasing into bracts. Flowering branches often erect, simple, rarely diffusely branched. Amongst popular hardy plants, few surpass Pentstemons for their usefulness and ornamental character in the mixed border or rock-garden, or for planting in beds by themselves. Their flowering season commences about June, and continues until after the appearance of frost, in autumn. Many of the species are very attractive, and are indispensable in the choicest collection of herbaceous plants; and a selection from the numerous varieties, improved so much of late years, is equally valuable for garden decoration and for cut flowers. Pentstemons are very varied in colour, and possess a naturally graceful and exceedingly floriferous habit. They may readily be propagated from seeds, and also from cuttings; the latter method being most generally adopted for perpetuating species and named varieties. Seeds may, however, sometimes be obtained, in favourable seasons, from plants that do not readily produce cuttings; under such circumstances, it is most important to collect them, if required for increasing stock. If preserved from named varieties, with a view to raising new ones, only such as have finely-formed flowers and distinct colours should be selected for seed-bearing. Seeds should be sown in pans or shallow boxes of light soil, about February, or early in March, and placed on a gentle hotbed. So soon as the seedlings are large enough to handle, they should be potted of singly, or pricked into boxes, and kept in a little warmth until established, when they may be gradually hardened and placed in a cold frame. Towards the end of May, plant them in a prepared border outside, where, if properly attended to, many will flower in the ensuing autumn. Seeds may also be sown, in the open ground, early in June, when the plants should be potted up in August, and preserved in cold frames through the winter, for flowering early the following year, after being again transferred to the outside. Cuttings root readily at almost any season when they are procurable. The best time to take them is in August and September, from the numerous side-growths that are usually plentiful at that season. They may be inserted in cutting-pots or pans, and placed in a close frame without artificial heat, or, failing this, under a hand glass, in a sheltered position, where coverings may be readily applied, if necessary, afterwards. For the winter, the plants succeed best in a cold frame; they may be put into permanent quarters again, outside, during April, or earlier, should the weather be favourable. It is important, first, to expose them for a few days, in order to thoroughly harden them, and avoid an undue check.

Although Pentstemons are hardy, they frequently succumb when subjected successively to wet and frost, the first-named being, perhaps, the more destructive of the two. It is important, therefore, to provide good drain-age, particularly for any of the more select species or varieties. A sandy loam, enriched with leaf mould or decayed manure, should be the compost prepared, if necessary, or these ingredients may be added to fairly good soil in borders for enriching it. Pentstemons well repay for liberal treatment and a rich soil. They require plenty of water throughout the summer; it is in winter when they suffer from being too wet. The best plan is to insert cuttings annually, and preserve a stock in a cold frame. If any old plants are to kept outside, they should be covered, in autumn, with ashes.

The species and varieties best known to gardeners are described below; except where otherwise indicated, they are hardy, herbaceous perennials. P. acuminatus (taper-pointed). fl. lilac, or changing to violet; corolla tube scarcely enlarged above; sterile filament bearded above; panicle strict, interrupted; cyme sessile, crowded. July. l. entire; radical ones petioled, oblong or ovate, obtuse, mucronulate; upper ones cordate, clasping. Stem erect, 1ft. high. 1827. (B. R. 1285.) P. angustifolius (narrow-leaved). A synonym of P. campanulatus. P. antirrhinoides (Snapdragon-like).* fl. lemon-yellow; corolla ventricose, naked, with large lips; sterile filament densely bearded on one side; peduncles two-leaved, often one-flowered. Summer. l. spathulate-lanceolate or oval, sub-petiolate, rather small, entire. h. 9in. to 18in. 1824. Plant sub-cinereous, much-branched. (B. M. 6157.) P. atropurpureus (dark purple). A synonym of P. campanulatus. P. attenuatus (attenuated) fl. yellowish-white or bluish-purple, variable; corolla more than 1/2in. long; inflorescence villous or viscous-pubescent. July. l. very glabrous, nearly always entire, rarely slightly denticulate; cauline ones lanceolate or oblong. h. 1 1/2ft. to 2ft. 1827. (B. R. 1295.) P. azureus (azure-blue).* fl., corolla of a beautiful azure-blue, reddish-purple at the base of the tube, more than 1in. long; panicle twiggy; peduncles one to three-flowered. August. l., cauline ones narrow or broad-or ovate-lanceolate; lower ones sometimes spathulate-oblong; upper ones closely sessile from the base, broadly sub-cordate-ovate or ovate-lanceolate. h. 1ft. 1858. Plant very glabrous, glaucous. (L. J. F. 211; P. F. G. 64.) P. a. Jaffrayanus (Jaffray's). fl. blue, large; peduncles one to five-flowered. l. oblong or oval, or the upper ones ovate-lanceolate or ovate, very glaucous. h. 1ft. 1858. (B. M. 5045, under name of P. Jaffrayanus.) P. baccharifolius (Baccharis-leaved).* fl. scarlet, showy, paniculate; corolla enlarged above, the upper lip sub-erect, the lower one reflexed. September. l. coriaceous, oblong, in rather distant pairs, nearly sessile, rigidly and acutely dentate. h. 1 1/2ft. 1848. A well-marked, showy, half-hardy sub-shrub. (B. M. 4627.) P. barbatus (bearded).* fl. varying from light pink-red to carmine; corolla tubular, the upper lip erect and concave, the lower deflexed and bearded at the throat; panicle twiggy, loose-flowered. July. l. entire; cauline ones sessile, lanceolate or linear-lanceolate. h. 3ft. 1794. Plant tall, many-flowered.(B. R. 1839, 21, a flesh-coloured variety, carneum.) SYNS. Chelone barbata (B. R. 116), C. ruelloides (A. B. R. 34). P. b. Torreyi (Torrey's).* fl. deep scarlet-red; throat of corolla naked or very slightly bearded; lips somewhat longer than in the type. Half-hardy. SYN. P. Torreyi.

P. breviflorus (short-flowered).* fl., corolla yellowish or flesh-coloured, pink-striped within, about 1/2in. long, the upper lip beset with viscid hairs; thyrse narrow, many-flowered, racemiform. September. l. lanceolate or oblong-lanceolate, denticulate, seldom (if ever) whorled, 1in. or more long. Branches slender, twiggy. h. 3ft. to 6ft. (B. R. 1946.) P. campanulatus (campanulate).* fl. varying in shades of pink, dark purple, violet, &c.; corolla tubular or campanulate-ventricose; sterile filament slightly bearded; panicle elongated, naked, raceme-like, secund. June. l., cauline ones distinctly lanceolate, ovate-lanceolate, or linear, argutely serrated. h. 1 1/2ft. 1794. (B. M. 1878, 3884.) SYNS. P. angustifolius (B. R. 1122; L. B. C. 420), P. atropurpureus (L. B. C. 1429), P. pulchellus (B. R. 1138; L. B. C. 1438), Chelone atropurpurea (S. B. F. G. 235), C. campanuloides (A. B. R. 40), C. rosea (S. B. F. G. 230).

P. centranthifolius (Centranthus-leaved). fl., corolla bright carmine, 1in. long, the lobes equal, except that the two upper ones are united higher, and equally spreading, scarcely longer than the breadth of the throat; sterile filament filiform, naked. June. l., lower ones oblong; upper ones obovate or lanceolate, amplexicaul. h. 2ft. 1858. (B. M. 5142.) SYN. Chelone centranthifolia (B. R. 1737).

P. Cobaea (Cobaea-flowered). fl. varying from dull reddish-purple to whitish; corolla 2in. long, inflated and broadly campanulate above the calyx, glabrous within; panicle few-flowered, viscous-pubescent. August. l. ovate or oblong, argutely serrated or denticulated. h. 1ft. (rarely 2ft.). 1835. Plant viscous-puberulous, half-hardy perennial. (B. M. 3465.) P. confertus (crowded-flowered).* fl. sulphur-colour, densely glomerate; sepals sometimes terminating in a long point; corolla narrow, nearly 1/2in. long; cymes often sessile. July. l. highly glabrous, usually entire; cauline ones lanceolate or oblong. h. 6in. to 18in. 1827. Plant very glabrous, strict. (B. R. 1260.) P. c. caeruleo-purpureus (bluish-purple). fl. with a bluish-purple corolla and very variable sepals. (B. M. 2954 and L. B. C. 1616, under name of P. procerus--an inappropriate one, as the plant is ordinarily one of the lowest of the genus.) P. cordifolius (cordate-leaved).* fl. bright scarlet, profusely produced; corolla tube about 1in., and lips 1/2in. long, tubular-cylindrical; sterile filament densely bearded. June. l. ovate or sub-cordate, usually denticulate or sparsely dentate, scabrid, with the veins impressed above. 1848. Plant sarmentose, and also climbing like a Lonicera, pruinose-puberulous or glabrous. Half-hardy sub-shrub. (B. M. 4497.) P. crassifolius (thick-leaved). A synonym of P. Menziesii Douglasii. P. deustus (blasted).* fl. yellowish, crowded; corolla 1/2 in. long, the tube slightly enlarged; sterile filament glabrous; cymes pedunculate. July. l. usually laciniately or pectinately serrate; cauline ones oblong or lanceolate. h. 1ft. 1827. Plant glabrous. (B. R. 1318.) P. diffusus (diffuse).* fl. purple, showy, in dense cymelets; corolla less than 1in. long; sterile filament bearded at apex; panicle often leafy. September. l. ovate or ovate-lanceolate; upper ones somewhat cordate-amplexicaul, thick, serrated. Stem ascendent. h. 1 1/2ft. 1826. Plant puberulous.(B. M. 3645; B. R. 1132.) "P. argutus (P. M. B. vi. 271) appears to be a form of this, connecting with P. Richardsonii" (Asa Gray). P. Eatoni (Eaton's).* fl. rich crimson-scarlet, disposed in terminal panicles; corolla widening towards the mouth, the lobes nearly equal. l., lower ones broadly ovate. h. 1 1/2ft. California, 1883. One of the best plants of the genus.

P. erianthera (woolly-anthered). A synonym of P. glaber. P. glaber (smooth).* fl. purple, violet, or blue, thyrsoid-paniculate, showy; corolla ventricose-ampliate; sterile filament shortly hairy towards the apex. August. l. entire, often glaucescent; cauline ones sessile, lanceolate or ovate-lanceolate. h. 6in. to 12in. 1811. Plant highly glabrous. (B. M. 1672.) SYNS. P. erianthera, P. Gordoni (B. M. 4319).

P. g. cyananthus (Cyananthus-like). fl. in a large, dense thyrse. l. broad, cordate-ovate; upper cauline ones acuminate. h. 3ft. (B. M. 4464, under name of P. cyananthus).

P. glabrus stenosepalus (glabrous, narrow-sepaled). A synonym of P. glaucus stenosepalus.

P. glandulosus (glandular). fl. violet or lilac, showy, large; corolla swollen above, with the limb shortly bilabiate; inflorescence paniculate. June. l. ample, slightly serrated; upper ones cordate-amplexicaul. h. 1 1/2ft. 1827. Plant viscous-pubescent. (B. M. 3688; B. R. 1262.) SYN. P. staticifolius (B. R. 1770).

P. glaucus (glaucous). fl. dull lilac or violet-purple, disposed in a somewhat compact thyrse; corolla less than 1in. long, enlarged above the base, with an ample throat. July. l. more or less glaucous; radical ones sub-ovate; cauline ones lanceolate or ovate-lanceolate, dilated at base. h. 9in. to 12in. 1827. (B. R. 1286.) P. g. stenosepalus (narrow-sepaled). fl., sepals lanceolate, long-acuminate; thyrse short, compact. SYN. P. glabrus stenosepalus. P. Gordoni (Gordon's). A synonym of P. glaber.

P. gracilis (slender).* fl. lilac-purple, or sometimes whitish, 3/4in. to 1in. long, tubular-funnel-shaped or almost cylindric; peduncles two to several-flowered. August. l., cauline ones mostly linear-lanceolate, 1in. to 3in. long, sometimes serrated; radical ones spathulate or oblong. Stems slender, 1ft. or less high. 1824. (B. M. 2945; L. B. C. 1541.) P. grandiflorus (large-flowered). fl. purple, very showy; corolla 1 1/2in. long; sterile filament hooked, shortly dilated and very slightly bearded at apex; cymelets two to five-flowered; pedicels shortened. July. l. all distinct; cauline ones, especially the upper ones, round, amplexicaul, or connate-perfoliate. h. 3ft. 1811.

P. Hartwegi (Hartweg's).* fl. scarlet or blood-colour; corolla shortly dilated upwards, 2in. long, tubular-funnel-shaped, with spreading lobes; peduncles two or three-flowered, elongated. June. l. lanceolate, or the upper ones dilated at base, amplexicaul, ovate-lanceolate, acuminate, entire. h. 2ft. 1825. See Fig. 78. (B. M. 3661 and B. R. 1838, 3, under name of P. gentianoides.) P. heterophyllus (variable-leaved).* fl. pink or rose-purple; corolla more than 1in. long, ventricose-funnel-shaped above, the limb shortly bilabiate; racemes twiggy; peduncles one, rarely two, flowered. July. l. entire; cauline ones linear-lanceolate or narrow-linear, attenuated at base. h. 1 1/2ft. 1834. Plant highly glabrous or pruinose-puberulous, scarcely glaucous. (B. M. 3853; B. R. 1899.) P. hirsutus (hairy). A synonym of P. pubescens.

P. humilis (dwarf). This species is closely related to P. gracilis. It differs, however, in the corolla being saturated with blue, and shorter, thyrse more upright; leaves paler; and habit dwarfer (3in. to 9in. high). 1874. (B. M. 6122.) P. labrosus (large-lipped). fl. 1 1/2in. long, horizontal or ascending; corolla scarlet, with lobes half as long as the narrow tube; panicle of long, slender, loose-flowered racemes. August. l., lower ones 4in. to 5in. long by 1/4 in. to 1/2in. broad, narrowly oblanceolate, narrowed into the petiole, quite entire, obtuse or sub-acute; upper leaves shorter, quite linear. Stem 3ft. to 4ft. high, red-purple below. 1884. (B. M. 6738.) P. laevigatus (polished). fl., corolla white, commonly tinged with purple, about 1in. long, abruptly campanulate-inflated above the tube; sterile filament thinly bearded above. Summer. l. firm, and somewhat glossy; cauline ones ovate or oblong-lanceolate, with subcordate, clasping base. h. 2ft. to 4ft. (B. M. 1425.) P. l. Digitalis (Foxglove-like). fl. white; corolla upwards of 1in. long, the tube narrowed from above, ampliate-campanulate; sterile filament sparsely bearded; thyrse naked, loose, many-flowered. August. l. scarcely serrulate; cauline ones 3in. to 6in. long, lanceolate, or the upper ones ovate-lanceolate, perceptibly attenuated. h. 1ft. 1824. (B. M. 2587.) SYN. Chelone Digitalis (S. B. F. G. 120).

P. Mackayanus (Mackay's). A synonym of P. pubescens. P. Menziesii Douglasii (Menzies', Douglas' var).* fl. lilac-purple, pink-red at base; corolla shortly bilabiate, with an enlarged throat; inflorescence racemose. June. l. thickly coriaceous, rather small, entire, usually obovate-lanceolate. h. 1ft. (B. R. xxiv. 16, under name of P. crassifolius.) The typical plant, Menziesii, has not been introduced. P. M. Scouleri (Scouler's). fl. purple. May. l. obovate-lanceolate or oblanceolate, mostly argutely serrated. h. 3ft. 1827 (B. R. 1277, under name of P. Scouleri.) P. Murrayanus (Murray's).* fl. red, showy, on slender pedicels; corolla 1 1/2 in. long, enlarged from below; sterile filament highly glabrous, hooked, and shortly dilated at apex. August. l., upper or cauline ones connate, orbicular. h. 2ft. to 3ft. 1835. (B. M. 3472.) P. ovatus (ovate). fl. purplish-blue, somewhat clustered; corolla tube scarcely enlarged; sterile filament bearded at apex. July. l. ovate or ovate-lanceolate, often argutely toothed; upper cauline ones sub-cordate at base and amplexicaul. h. 4ft. 1826. Plant puberulous. (B. M. 2903; S. B. F. G. ser. ii. 211.) P. Palmeri (Palmer's). fl; pale purple, on slender pedicels; corolla broadly ampliate-campanulate above the calyx; panicle naked, raceme-like, twiggy, loose-flowered; peduncles two or three-flowered. Summer. l. lanceolate-ligulate, argutely denticulate, and, as well as the stem, glaucescent; upper ones semi-amplexicaul; lower ones spathulate, attenuated into the petioles. h. 1 1/2ft. 1873. (B. M. 6064.) P. pubescens (downy).* fl. dull violet or purple, or partly whitish, disposed in a loose-flowered thyrse; corolla enlarged above, and shortly obcompressed; sterile filament long, and densely bearded. August. l., cauline ones linear-or ovate-lanceolate, the uppermost ones reduced to small, bracts. h. 1ft. to 3ft. 1834. Plant viscous-pubescent or almost glabrous. SYNS. P. hirsutus (B. M. 1424), P. Mackayanus.

P. pulchellus (pretty). A synonym of P. campanulatus. P. Richardsonii (Richardson's). fl. violet, disposed in a loose panicle; corolla 1in. long; sterile filament slightly bearded at apex. July. l. ovate-lanceolate or narrow-lanceolate, incised or laciniate-pinnatifid. Stem usually branched; branches spreading. h. 1 1/2ft. 1825. Plant almost glabrous. (B. M. 3391; B. R. 1121; L. B. C. 1641.) P. spectabilis (remarkable). fl. bluish-purple; corolla 1in. long, the tube inflated above, the lobes very broad and much spreading; sterile filament glabrous; cymelets three to nine-flowered, pedunculate; panicle loose, elongated. June. l. thick, ovate-lanceolate, coriaceous; upper cauline ones amplexica??ul, connate. h. 2ft. 1816. Plant highly glabrous. (B. M. 5260.) P. staticifolius (Statice-leaved). A synonym of P. glandulosus. P. Torreyi (Torrey's). A synonym of P. barbatus Torreyi. P. triphyllus (three-leaved). fl. violet, disposed in a loose, leafy panicle; corolla 1/2in. long, slightly enlarged above; sterile filament densely bearded. July. l. lanceolate or linear, few-toothed or pinnatifid; lower ones ternate or quaternate, upper ones sometimes opposite. h. 1 1/2ft. 1827. Plant almost glabrous, branched. (B. R. 1245.) P. venustus (charming).* fl. purple; corolla upwards of 1in. long, dilated upwards from a narrow tube; sterile filament densely bearded at apex, the lobes ciliated; panicle thyrsoid, rather loose. June. l. ovate, or ovate-lanceolate; upper ones sub-cordate, amplexicaul, thickly serrated. Stem ascendent. h. 2ft. 1827. Plant puberulous. (B. R. 1309.) P. Wrightii (Wright's). fl. rosy-red; corolla less than 1in. long, dilated-ventricose above, with an ample limb of round, much-spreading lobes; sterile filament long, and densely bearded; cymelets or panicles loose, twiggy, few-flowered. June. l., lower ones oblong; upper ones sub-obovate or lanceolate, amplexicaul h. 2ft. 1850. (B. M. 4601.) Varieties. The seedling or garden varieties of Pentstemon have now attained a high degree of excellence, and, as they are so readily raised, other additions are annually made, which represent improvement in form, size, or colour-markings, the result of selection, which the florist or specialist is rigidly prosecuting. The garden varieties are principally the offspring of P. Cobaea and P. Hartwegi, though other species may also have had something to do with the origin. Subjoined is a selection from the best varieties in cultivation. Many of the old ones are now of sufficient merit to hold their own against new comers.

AGNES LAING, dark rose, throat fine white; splendid form. ALEXANDER TOD, rosy-pink, throat blotched, dense panicle; extra fine. AMELIA, rosy-salmon, mouth and throat dark blotched, large flowers. ARCHIBALD FORBES, magenta, throat white, slightly pencilled, large flower and panicle. BLACK KNIGHT, maroon, throat shaded white; good form; a fine variety. BRIDESMAID, French white, tipped pink; an acquisition. CANDIDATE, bright carmine-scarlet, throat white, lobes belted rose; extra fine. DECISION, magenta-crimson, throat white, pencilled crimson; large and fine. DIANE, dark violet-rose, throat veined and spotted purple. ECCENTRIC, crimson, throat white, blotched and pencilled. E. J. LOWE, vivid scarlet, throat finely pencilled. FLEURON, deep red, tinted crimson and maroon, throat pure white, heavily pencilled; distinct. GEORGE M'ROBERT, puce-purple, throat blotched, close panicle; distinct and fine. H. CANNELL, bright rose, throat pure white, heavily pencilled crimson-maroon; large flowers and panicle. HELEN WOOD, purplish-crimson, throat white, slightly pencilled. JAMES BEGG, carmine-magenta, throat white; large open flower; very showy. JAMES THOMSON, bright vermilion, throat white; very fine. JESSIE FORBES, reddish-purple, throat pure white, heavily pencilled crimson. KING OF PENTSTEMONS, violet-purple, throat white, pencilled; flowers large, and of fine form. LADY MARGARET, maroon, throat white, heavily pencilled, fine panicle. MISS F. HOPE, pure white, slightly suffused pink; one of the best of its class. MISS HAMPTON, mulberry, throat blotched, pure white spot; fine. MISS WWATSON, maroon-purple, throat chocolate, pencilled and spotted white; very fine. MRS. ALEXANDER M'KINNON, mauve-crimson, throat white, finely pencilled crimson. MRS. GREEN, rose, throat pure white; extra. MRS. MANN THOMSON, blue, throat pure white; large, and very showy. MRS. NIXON, dark mauve-purple, throat pure white; large flower. MRS STYLES, tube dark lilac, mouth claret; large flower. PILRIG PARK, rosy-purple, throat blotched, fine panicle; extra. P. KLEIN, bright purplish-pink, throat pure white; flowers large and fine. PROGRES, rosy-crimson, throat pure white, pencilled; extra. ROBERT DODDS, reddish-crimson, throat pure white; very fine. ROBERT WARD, scarlet, throat blotched; extra. THE CLOWN, rosy-red, throat white, beautifully marbled crimson; fine. THE FAVOURITE, carmine-rose, throat pure white, pencilled deep red; large flowers and panicle. WILLIAM MILLER, cherry-crimson, throat white, heavily blotched chocolate.