Hackelia diffusa var. diffusa
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Authority
Gentry, Johnnie L. & Carr, Robert L. 1976. A revision of the genus Hackelia (Boraginaceae) in North America north of Mexico. Mem. New York Bot. Gard. 26: 121-227.
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Family
Boraginaceae
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Scientific Name
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Description
Variety Description - Perennial, (2-)4-6(-7) cm tall; stems few, erect or ascending, internodes long near the base, short near midstem, the plant therefore appearing leafy near the middle; pubescence strongly spreading, hirsute, becoming antrorsely appressed in the inflorescence. Radical leaves few to many, 12-23 cm long, 10-26 mm wide, elliptic, petiolate for ca. 1/3 (1/2) their length, hirsute, all but the lowermost cauline leaves sessile, the lower ones 9-14 cm long, 12-17 mm wide, elliptic, becoming lanceolate or linear-lanceolate above, at midstem 6-10 cm long and 6-15(-18) mm wide. Pedicel 5-8(-ll) mm long in fruit. Calyx 2.5-4.2 mm long, lanceolate or linear-lanceolate. Corolla limb blue or cream, with a yellowish throat, 7-13 mm wide. Fornices with appendages papillate-puberulent to short pilose, not always evidently emarginate. Anthers 0.8-1.2 mm long. Nutlets 3.0-3.6 mm long, ovate; dorsal surface rough, verrucose-hispidulous, the intramarginal prickles distinct, ca. 10; prominent marginal prickles distinct to their bases, 2.0-3.3 mm long, these alternating with 1-3 short glochidia. Chromosome number, 2n = 48.
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Discussion
Echinospermum diffusum Dougl. ex Lehm., Stirp. Pug. 2: 23.1830. Lappula diffusa (Dougl. ex Lehm.) Greene, Pittonia 2: 182. 1891. Lappula saxatilis Piper, Bull. Torrey Club 29: 541. 1902. Hackelia saxatilis (Piper) Brand, Pflanzenr. IV. 252(Heft 97): 133. 1931. Type: WASHINGTON. Klickitat County: Klickitat River, June 12, 1885, W. N. Suksdorf 592 (holotype, GH!). Type. OREGON. On moist rocks near the Grand Rapids of the Columbia, 1825, Douglas s.n. (holotype, K, type photo GH!). Hackelia diffusa var diffusa as typified by David Douglas’s collection from “near the Grand Rapids of the Columbia” is a somewhat variable taxon recognized by its rather long, soft, spreading pubescence. Typical H. diffusa var diffusa can be found in the Columbia Gorge as far east as Hood River. Between Hood River and The Dalles one finds forms transitional to H. diffusa var cottonii. The Washington collections of this taxon also show intermediacy to var cottonii or in some cases indicate possible introgression with H. diffusa var arida. Contrary to what some authors indicate, blue flowered populations are very common and indeed may represent the “ancestral” condition for H. diffusa var diffusa. After Lehmann originally described this taxon, along with Hackelia ciliata and H. floribunda, very little consideration was given the genus until work by Gray was started near the end of the century. Unfortunately Gray misinterpreted Lehmann’s type and description, and associated the epithet diffusa with what is now known as H. micrantha. Aware that Gray had seen the type, Piper, in his revision of 1902, chose to follow Gray’s interpretation of this taxon, and as a result he described the “new species” H. saxatilis, based on a Suksdorf collection from the Klickitat River. This collection is quite obviously good H. diffusa as typified by the Douglas specimen, but it was described as new as a result of Gray’s original error being perpetuated by Piper. In 1923 this interpretation was challenged by I. M. Johnston. He removed from Hackelia diffusa the material now referred to H. micrantha and placed this element with H. floribunda. Although currently not accepted, this was a reasonable taxonomic alignment based on morphological grounds alone. Unfortunately his understanding of the western United States members of the genus was not clear, and he too misinterpreted the original Lehmann plant, although to a lesser degree than had Gray. He placed H. saxatilis in synonymy with H. arida var cusickii, which indicates that to him, the epithet diffusa referred to the plant of south-central Washington named H. hendersonii by Piper, and was not the species which we now know is typified by the Douglas specimen. There is little doubt that the current interpretation of this taxon is correct. Although Lehmann’s description leaves some room for doubt, the type and type-locality do not. What Douglas called the Grand Rapids is now known as the Cascades, and this area falls well within the known range of this taxon. There is no other Hackelia found in the Cascades Locks region.
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Distribution
Habitat and distribution (Fig. 18). Shaded areas, cliffs, talus, wooded flats and slopes at elevations of 300 to 1,200 feet, in the Columbia River Gorge of Oregon from Corbett to The Dalles and in Washington in the Klickitat and Big White Salmon River drainages; also in the Thompson and Fraser River canyons of British Columbia, Canada. Flowers in (April) May and June.
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