The Penstemons of Western Canada

1

THE PENSTEMONS OF WESTERN CANADA

By Pauline Olthof

INTRODUCTION

In this article I intend to include a very large area, stretching from the edge of the Canadian Shield in Manitoba across the Prairies to the Foothills of Western Alberta as well as the Cordilleran Region of British Columbia. The reason for taking this large an area is that in describing the Penstemons of the Province of Alberta alone, large parts of Saskatchewan an d Manitoba to the east, and parts of British Columbia to the west would have to be included as well. Besides, in my study for this article, I was struck by the emphasis that could be placed on the influence of environment on the distribution of plants if British Columbia, Saskatchewan, and Manitoba were included in the article.

Great geological and geographical differences occur within this large area, and these differences affect climate, aspects (exposure), and soil formation. All of this In turn affects what plants are going to be able to grow in any given area within the larger region, Including the Penstemons that are the subject of this writing.

The Prairies generally rise from lower elevations of between 1500 and 2600 feet in Manitoba to about 3500 feet 1n Alberta. A few low hills, such as the Cypress Hills of southern Alberta and Saskatchewan, are erosion remnants of a previous higher-elevation peneplain and now still rise well above the general level of the Plains. The Cypress Hills and a few other such hills have never been glaciated and therefore support a unique flora which includes pre-glacial species. No such unglaciated areas occur in British Columbia, but, strangely enough, almost the entire western half of the Yukon escaped glaciation during the Pleistocene. Most of these erosion remnant hills receive higher precipitation than the surrounding terrain and as a result, support trees and a woodland flora under these trees.

The Cordilleran region in Canada is divided longitudinally into three great belts: the Eastern System, comprising the RockyMountains proper and the Foothills, the Interior System, which consists largely of sedimentary rocks that were intricately folded and faulted during the Tertiary Laramide Orogeny. They contain much limestone.

The Interior System includes lava flows and intrusives as well as much metamorphic rock in its bedrock and various depths of glacial drift and lake sediments as cover. The Coast Rangesare volcanic and also include much metamorphic material. Both the Rocky Mountains and the Coast Ranges reach elevations well over 10,000 feet, while the Interior System generally rises from an elevation of below 3000 feet in the Fraser Basin to the northeast to above 6000 feet in the Columbia Mountains, but the general elevation is between 4000 and 5000 feet.

This topography naturally influences climate which, generally speaking, is dry in the Prairie Region (Great Plains), getting drier as one moves west. The high mountain ranges of the Rockies and Coast Ranges of Western B.C. act as precipitation barriers leaving extremely dry areas directly to the east: the Okanagan in British Columbia.and Alberta and Saskatchewan behind the Rockies proper. The vegetation reflects these conditions: the Okanagan and the southernmost parts of Alberta and Saskatchewan have semi-desert conditions with cacti and, in southern Alberta, Yuccas.

Prairie soils tend to be deep, from black chernozems in Manitoba gradually changing westward to less deep, brown soils in Saskatchewan and Alberta. In the southern parts of these latter two Provinces, salts appear at the surface in many places. In the Cordilleran Region, a large and varied array of soils may be found, depending on bedrock, depth of glacial drift, and postglacial erosion. All these conditions are reflected in the vegetation as are slope and aspect (the way a location faces, such as south or north, and thus how much solar radiation is received). Nevertheless, within the genus Penstemon in this large area of study, there occur some overlaps of distribution of Penstemon species (and many other plant species) that appear to completely disregard all differences.

The following table of the Penstemon species, listed for the Prairies and for British Columbia, has been drawn up in such a way that the occurrence of species in each region as well asoverlaps In occurrences may be seen at a glance. Since many of the species listed in the table also occur in adjacent parts of the United States, this article intends to concentrate more on their areal distribution and site preferences than on descriptions of each species, most of which appear in one or the other of the Lodewick Penstemon Field Identifiers as well.

DISTRIBUTION OVERVIEW

Based on the broad physiographic characteristics of the terrain covered in this article, as well as on the preceding table, it seemed best to divide the 19 species of Penstemon accordingly:

Group I - True Prairie Species:

Penstemon albidus Nutt., (white beardtongue)

This species is common on dry prairies and hillsides throughout the south-central and southwestern parts of the Canadian Prairies from Alberta to southern Manitoba; ranges south to New Mexico, Texas, and Oklahoma; east to Iowa and Minnesota. It often occurs in grasslands and on limestone (Venning, 1984). It is unmistakable because of its white flowers which may be tinged with violet. Buds reddish.

Flowers from June to July.Identifier Section I.

Penstemon gracilisNutt., (lilac-flowered beardtongue.)

A slender and erect species, 15 to 50 cm (6-20 inches) tall, with flowers borne in clusters of 2-3 1n the axils of the upper leaves, forming an open panicle of pale lilac or pale violet flowers. It is a characteristic species of the Northern Great Plains, of moist to dry prairie grasslands, often in sandy or rocky soil, ranging from British Columbiato western Ontario, and south to New Mexico, Iowa, Nebraska, and Wisconsin. Flowers from June to July, usually in mid-June. Identifier Section I.

In British Columbia this only occurs 1n the prairie lands of the Peace River District in northeastern

B.C.

Penstemon puberulentus Rydb.[not listed as a penstemon species Ed.]

"Rare, but has been reported from the south-central parts (of the Canadian Prairies) adjacent to the International Boundary. General distribution is in Idaho and Oregon." (Budd & Best, 1969, c!964). It has not been found in any of the Penstemon Field Identifier Sections, and no time of flowering has been found in any reference either.

Group II - "Transition" Species:

Under this heading are listed those species that occurin both Alberta and British Columbia EAST of the Cascades/Coast Mountains:

Penstemon albertinus Greene

(Southeastern B.C. and extreme SW Alberta.) A handsome plant, about 20 cm (8 inches) tall, with many flower stems from a thick, woody rootstock. Flowers in whorls, 1-1/2 to 2 cm long, purplish blue. It is a plant of exposed dry gravelly slopes or rocky ridges. In Alberta 1t occurs only in the extreme southwest of the Province (Moss, 1983), but in WatertonLakesNational Park it is rather common at lower and middle elevations throughout the Park.

In southeastern B.C. and south into central Idaho and western Montana (both sides of the Continental Divide), it appears to "climb" to higher elevations. In the more southerly parts of its range it can be found up to sub-alpine elevations. Penstemon albertinus flowers from May to July.

Identifier Section I.

Penstemon confertusDougl. (Southern B.C. and western Alberta.)

A very common and widespread Penstemon, not only in Albertabut also in B.C., from the OkanaganValleyeastwards, eastinto Saskatchewan south to central Oregon and westernMontana. It is a plant of fairly moist, open or wooded
places, often in meadows or along streams, to be found inthe west up to elevations of 2300 m (7500 feet) in themountains. I collected this for the Herbarium of theUniversity of Calgary from the foot of an avalanche slope at
about 900 m (3000 feet) elevation in KootenayNational Park,in 1970 and 1971.

Identifier Section I.

Penstemon ellipticusCoult & Fisher (Southeastern B.C. and SW Alberta.)

Low, mat-forming plants from a much-branched woody base, to be found on rock outcroppings, cliff faces and similar exposed sites, mostly between 2000 and 2800 m (6500 and 9000 feet) elevation. A beautiful and rather common plant in WatertonLakesNational Park which might be confused with P^ lyallii; the latter has very narrow and long leaves and more flowers in open clusters. Penstemon ellipticus can also be confused with P. fruticosus: it too is woody and shrubby and has very large, violet-blue flowers on many stems from a stout rootstock and similar smallish, mostly entire, lanceolate leaves. In P. ellipticus specimens examined in the University of Calgary Herbarium, the leaves were slightly larger and the flowers somewhat smaller than in P^ fruticosus. and R^ fruticosus also appears to be more woody.

Southwestern Alberta and southeastern B.C., south to northern Idaho and northwestern Montana. In B.C. found in the Kootenay and ColumbiaValleys.

Flowers from late Juneinto August, sometimes September.

Identifier Section I.

Penstemon eriantherus Pursh

(Extreme SW Alberta and Southeastern B.C.) There are four varieties of this species in the Pacific Northwest as defined by Hitchcock et al. (Vol. 4, 1959, p. 384): vars. whitedii and argillosus. which are sharply distinguished from var. eriantherus by the anthers and inflorescence as well as geography - "and if only these three taxa had to be considered, the maintenance of two species would be well justified. The var. redactus. however, so completely bridges the differences that all four taxa must be considered as geographic races of a single species." (Hitchcock et al, Vol. 4, 1959, p. 384). In western Canada only var. eriantherus occurs, and that only in extreme southwestern Alberta and southeastern B.C., the distribution stretching east to North Dakota and Nebraska and south to Oregon and central Washington and Colorado.

Dry, open places in the prairies and foothills, sometimes ascending to moderate elevations in the mountains.

On May 20, 1971, I collected Penstemon er1 anthems (var. eriantherus) at Columbia Lookout along B.C. Highway 93/95 (a northward continuation of Idaho Highway 95). This specimen was collected for the University of Calgary Herbarium, but on June 3, 1978, another specimen was collected for my own Herbarium from a moist meadow off Highway 2 in southern Alberta, just northwest of FortMcLeod. (This was also photographed). Both Herbarium specimens were examined again. They are plants of about 40 cm tall, with several stems arising from a branched, largely underground caudex. The plants are glandular villous in the inflorescence, with entire to more or less toothed leaves, the basal ones poorly developed in the two specimens examined, up to 13 cm long and 2 cm wide: robust plants. Inflorescence of several distinct whorls (verticlllasters), with elongated calyx with lanceolate lobes. Corolla glandular-hairy on the outside, pale lavender to reddish purple in the U. of C. Herbarium specimen, but a deep, rich purple-blue in my own, 2-4 cm long, strongly inflated distally, to almost 1-1/2 cm wide at the mouth, the lower lip slightly longer than the upper one; palate strongly bearded, and so is the staminode which is exserted. Pollen sacs are relatively broad, as wide as long or about 1-1/2 times as long as wide, which is the distinguishing feature of var. eriantherus.

Flowers from May to July.

Identifier Section I.

Penstemon fruticosus (Pursh) Greene

(Southern Alberta and British Columbia.)

This Is a variable species, a semi-evergreen, shrubby species with some leaves turning reddish in the fall and then dropping, the rest dull green and remaining on the plant. Commonly forming mats of 10 to 30 cm tall, with entire, elliptical, slightly leathery leaves. In var. scouleri (Lindl.) Pennell & Keck, the leaves are much narrower and obscurely toothed. Flowers, up to 5 cm long, usually are blue-lavender but may vary to white or pink. Along the old Highway 3 in southern B.C., these conspicuous flowers could be seen on almost every other rocky ridge along the Highway to the delight of all passing flower lovers, but since this Highway has now been straightened, this exquisite pleasure is now lost to "progress," alas. The range of P.fruticosus is strictly EAST of the Cascades, but from there on all across southern B.C. and southwestern Alberta, south Into Montana, Wyoming and central Oregon where it may be found on dry, rocky ledges and slopes, from low to quite high (alpine!) elevations.

Flowers from May to August.

Identifier Section I.

Penstemon lyallii A. Gray

(Confined to the Crow's Nest Pass area of extreme SW Alberta and SE British Columbia)

This species has "absorbed" Penstemon linearifolius Coult. & Fisher (Moss, 1983), which name is now no longer valid. Penstemon lyalli is an essentially glabrous, few-stemmed plant, distinctly woody at the base, up to 60 cm tall, with erect leafy stems. The flowers are lilac-blue, like those of P. fruticosus; a few with a pinkish tinge. Corolla with petals all about the same length. Staminodes ("beards") not exserted. It Is a rather common and very striking plant at mid-elevations on rocky slopes, shale slides, and gravel bars along streams. In Alberta and B.C. It is confined to the Crow's Nest Pass area, but the range extends south into northern Montana and Idaho.

Flowers from June to early August. Identifier Section I.

'This sharply marked species evidently hybridizes with the superficially very different P. ellipticus in Montana." (Hitchcock et al., Vol. 4, 1959, page 394.)

Since both species also occur in Canada and their ranges in this country overlap, it should be expected that similar hybrids will be encountered here also, although I have found no mention of this in any of the references consulted so far. Both species are deciduous, but P.lyallii is herbaceous, whereas P. ellipticus is shrubby. Penstemon lyallii is the tallest member of the genus in the Canadian Rocky Mountains Parks, where, together with P. acuminatus Dougl. and P.albidus Nutt., It is found only in WatertonLakesNational Park; the light-blue-flowered P.albertinus Greene, however, has been collected once in BanffNational Park (Porsild, 1974).

Penstemon nitidus Dougl. ex Benth.

(SW Alberta and Crow's NestPass area In British Columbia.) Smooth blue beardtongue is unmistakable because of its bluish, almost fleshy, broadly ovate leaves and usually brilliantly blue flowers. The plant grows to about 35 cm tall, on open, often grassy, bluffs and knolls, grassy hillsides and plains, disturbed areas, and sometimes on talus at moderate altitudes in the mountains, mostly below 1700 m (5500 feet). Southwestern Alberta and the Crow's Nest Pass area in B.C., south to northern Idaho and western Montana, SE to northern Wyoming and northeastern Colorado, east to western North Dakota and southern Manitoba. It is very common in southern Alberta. The flowers sometime appear to be rosy-pink rather than the more common bright blue; some pink-flowered specimens were encountered in the University of Calgary Herbarium. These were collected in southwestern Saskatchewan.

Flowers from May to July.

Identifier Section I.

Penstemon nitidus apparently was much more widespread "throughout the entire south-central and southwestern parts (of the Canadian Prairies)." (Budd & Best, 1969, c!964). If so, we have here an example of the shrinking of the range of this species since Budd and Best's book was researched and written, which is a time period of over 20 years. This kind of phenomenon stresses the need for accurate recording of all collections and findings of plant species, and for keeping these records up to date, and the distribution ranges indicated on topographical maps, as is done at most universities' Herbaria. This allows for range comparisons over time so that one can be aware of distribution changes over time and of many plant species, which can indicate changes in vegetation associations over long intervals.

Penstemon procerusDougl. ex Grah.

(Southeastern B.C. and SW Alberta to southern Manitoba.) There are several good specimens of this species in my own Herbarium which show that, but for the deep, velvety blue flowers, this species- could have been P^ confertus (pale-yellow-flowered). Since the ranges of these two species partly overlap, it is helpful that the flower colors are so strikingly different.

According to Hitchcock et al. (1959), P. procerus may also be P^ ochroleucus or £._ whitedii. but Moss (1983) does not mention either of these latter two species in the description of P^ procerus. probably because neither of the other two species have been recorded for Canada in either Moss or any of the other references consulted for this article, so that they probably do indeed not occur in Canada. Taylor (1974) gives the following distribution and habitat discription for the species: "Dry soil, often in open woods; rocky slopes from mid-altitudes to above timberline east of the Coast Mountains, Alaska to Alberta and Saskatchewan, south to California and Colorado. General except on Vancouver Island." Moss (1983) gives a distribution range which did not include Alaska but at the other end extends into southwestern Manitoba.