| Section 6 » Family Salicaceae |
Show/Hide Synonym
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| Salix occidentalis | < | Salix humilis | Godfrey and Wooten (1979, 1981) | | | Salix occidentalis | < | Salix humilis | Radford, Ahles, and Bell (1968) | | | Salix occidentalis | = | Salix humilis var. microphylla | Fernald (1950) | | | Salix occidentalis | = | Salix humilis var. microphylla | Wofford (1989) | | | Salix occidentalis | = | Salix humilis var. microphylla | Chen et al. (2010). Key adapted from Z and FNA. | | | Salix occidentalis | = | Salix tristis | Gleason (1952) | | | Salix occidentalis | = | Salix tristis | Small (1933, 1938) | | | Salix occidentalis | = | Salix tristis | Flora of West Virginia | | | Salix occidentalis | = | Salix humilis var. tristis | Flora of North America (1993b, 1997, 2000, 2002a, 2002b, 2003a, 2004b, 2005, 2006a, 2006b, 2006c, 2007a, 2009, 2010) | | | Salix occidentalis | = | Salix humilis var. tristis | Kartesz (1999) | | | Salix occidentalis | = | Salix humilis var. tristis | | | | Salix occidentalis | = | Salix humilis var. tristis | | | | Source: Weakley's Flora |
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| Author | Walter | |
| Distribution | This poorly-known species occurs sparingly over much of the state, including parts of the Coastal Plain. The range map (below) is certainly incomplete, owing to taxonomic confusion with S. humilis, as it was split from that species recently. It is presumed that botanists have simply overlooked or failed to recognize this “new” species. For example, the Digital Atlas of the Virginia Flora shows its range across the entire state, even to the southeastern corner; and Weakley (2018) shows its being found in all three NC provinces.
Weakley (2018) gives the overall range as “ME to ND, south to GA, LA, and OK.” This is a smaller range than for S. humilis, though the NC portion of the range is somewhat similar.
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| Abundance | Probably rather rare to uncommon, at least in the Mountains and eastern Piedmont, and probably the same abundance in the remainder of the Piedmont, where specimens seem to be lacking. Weakley's (2018) map shows it "uncommon" in both the Mountains and Piedmont, and "rare" in the Coastal Plain. This species should be added to the NC NHP's Watch List, owing to a near complete lack of knowledge of its distribution and abundance in the state. The S3 state rank is likely incorrect, as this is presumed to be the rank for the original/combined S. humilis before the split; and this is the identical rank for the seemingly much more numerous S. humilis after the species split. This website recommends a state rank of S2?, certainly with a "?", owing to the scarcity of data for it. | |
| Habitat | This species occurs in dry and sunny habitats, especially in rocky and often barren areas. It can be found in powerline clearings, wooded borders, rocky wooded margins, etc., especially so over high pH soils. At times it can be found in ditches and other damp, disturbed areas. (The habitats appear to be very similar to those of S. humilis, but more information about NC habitats is needed.) | |
| Phenology | Blooms and fruits from March to May. | |
| Identification | This is a rather low deciduous shrub, typically just 1-3 feet tall. It has narrow, oblanceolate (widest above the middle) leaves that have rolled margins and have dense white hairs below. The leaves are small, barely 1-1.5 inches long on average; they are also quite narrow, seldom more than 1/3-inch wide. Leaves are often crowded on the fuzzy stems; in addition, the leaf tapers to the stem and thus is practically sessile. The very similar but larger S. humilis has longer and wider leaves with a distinct petiole, leaves nearly elliptic in shape, and scarcely rolled margins. The leaves of S. occidentalis resemble several species of narrow-leaved oaks, such as Willow Oak (Quercus phellos) or Laurel Oak (Q. laurifolia), though the willow leaves are smaller. Both species tend to occur in colonies. | |
| Taxonomic Comments | This taxon has previously been considered as a variety of Salix humilis, as either S. humilis var. microphylla or S. humilis var. tristis. However, a few older references had these split into species, and this was typically named as Salix tristis. RAB (1968) did not even have these two fairly distinct taxa split out at all. Weakley (2018) and this listserve (NatureServe) are in agreement with splitting this out as a good species with the name of S. occidentalis.
The genus Salix is a very large and complex group of plants that vary from ground-hugging Arctic belly plants to huge trees. There are 113 species in North America alone, including introduced species. They are extremely important to browsing mammals -- rabbits, deer, elk, muskox, moose, many rodents -- and browsing birds like ptarmigan. Many birds use them to nest in. Here in NC we only have a small number of native species (5) and so do not appreciate the ecological importance of willows. We highly recommend reading the introductory pages of George Argus's FNA treatment (2010) and his excellent monograph on the willows of the southeastern U.S. (1986). The latter has drawings and descriptions of all southeastern U.S. taxa. Due to natural and horticultural hybridization, some plants will not key cleanly and you may have to compare your specimen with others verified by Argus. | |
| Other Common Name(s) | Sage Willow, Dwarf Prairie Willow | |
| State Rank | S3 [S2?] | |
| Global Rank | G5 | |
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