Monographs Details: Hackelia cinerea (Piper) I.M.Johnst.
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.
Description:Species Description - Moderately stout perennial, (2.5-)5-7 dm tall; stems several, rarely solitary, erect or ascending, antrorosely strigose in the inflorescence, retrorsely strigose at base, with coarser spreading hairs throughout. Radical leaves few to several, (3-)8-15(-21) cm long, (3-)8-13(-20) mm wide, narrowly elliptic, having a narrowly winged petiole for ca. 1/3(1/2) their length, the upper surface bearing subappressed sericeous pubescence and much smaller strigose or rarely tomentose pubescence, the lower surface having the coarser hairs restricted mainly to the margins and main veins, the finer hairs usually tomentose; much denser than above; cauline leaves mostly sessile, the lower ones 4-8 cm long, 3-5 mm wide, linear, early deciduous, those at midstem 4-7 cm long, 6-9 mm wide, lanceolate or linear-lanceolate, becoming reduced to minute bracts in the inflorescence, pubescence similar to that of the radical leaves but usually less dense. Pedicel 7-11 mm long in fruit. Calyx 2-3 mm long lanceolate. Corolla limb white with a yellowish throat, 6-12 mm wide. Fornices with appendages obscurely if at all emarginate, strongly papillate-hairy. Anthers (0.7-)0.8-1.1 mm long. Nutlets 3.2-3.8 mm long, ovate; dorsal surface very rough, verrucose-hispidulous, the intramarginal prickles distinct, 10-16; prominent marginal prickles 1.2-2.0 mm long, connate for about 1/3 their length, these alternating with 1-3 much smaller prickles. Chromosome number, 2n = 48.

Discussion:Lappula cinerea Piper, Bull. Torrey Club 29: 544. 1902.Type. IDAHO. Salmon River bluffs, elevation 2,500 feet, July 2, 1895, L. F. Henderson 3006 (holotype, US!). Hackelia cinerea is quite uniform over most of its range, and it is for that reason that we choose not to merge this species with the “arida-diffusa” complex. The uniformly sericeous condition on the upper surface of the leaves and the shape, texture, and surface of the fornices readily distinguish this taxon from other Northwest members of the genus. In most other characters, however, there is overlap with H. diffusa var arida and H. ciliata. If it were not for the differences in the corolla and mature nutlets, this taxon would at best be difficult to distinguish from some populations of H. patens var patens. These taxa are partially sympatric in Idaho but there is no evidence of interbreeding. An interesting population of plants can be found near the mouth of Little Van Buren Creek (see Quentin Jones 131, R. L. Carr 510). Throughout its range Hackelia cinerea exhibits a fusion of the marginal prickles of the nutlet to about one-third their length, but in the population mentioned above the marginal prickles are distinct to their bases or nearly so. This population also has the nutlets smaller, there are fewer intramarginal prickles (6-10), the intramarginal prickles are longer, and the marginal prickles are not flared inward to form a cupulate border which is common in the other H. cinerea populations. Despite the above listed characteristics and the fact that the Little Van Buren Creek site appears more mesic, the plants are best classified as H. cinerea. There are other somewhat unusual populations of Hackelia cinerea, but these involve mostly differences in stature; for instance there appear to be one or more alpine ecotypes. Although further study is necessary, some collections which may represent this alpine “ecotype” are Macbride & Payson 3577, and Hitchcock & Muhlick 10813. The Hitchcock and Muhlick specimen from Castle Peak in Custer County is only about 2 dm tall and reduced overall from the “normal” H. cinerea. When transplanted from this region to a more mesic “greenhouse” condition, plants do not gain the stature of individuals restricted to lower altitudes. Another population that tends towards a reduced size is the disjunct population found near Spokane, Washington. This population of probably less than 100 plants is apparently restricted to a small section of Deep Creek Canyon. The habitat there is quite different from that normally occupied by H. cinerea, the plants being found in cracks and depressions of the basalt cliffs and rarely in talus. The population is not reproducing well and probably represents a fairly recent introduction of H. cinerea to the area. This would help to explain why the plant does not occupy a much larger range in an area that has an excess of sandy-gravelly talus. Perhaps the quantity of moisture and its duration of availability differ and in some way restrict the population to its present location. Material collected in Montana tends to have a rather large pandurate protuberance on the fornices of the corolla. This is different from the smaller, rather deltoid protuberance found throughout most of the range of Hackelia cinerea and may represent some introgression with H. ciliata. The Montana material also tends to have thinner, more linear leaves, and the pubescence density increases toward that found in H. ciliata and H. diffusa var arida. Although these Montana populations are closer to the Spokane region, the above mentioned characteristics tend to eliminate them as the source of the Deep Creek Canyon population, because it is morphologically more like the “typical” H. cinerea.
Distribution:United States of America North America|