Astragalus Identification (Washington State)

Relatively jargon-free guide to Washington State Astragalus species.

Astragalus columbianum - Not yet observed (rare). Seems to look a lot like a white A. succumbens with much narrower leaflets.

Astragalus conjunctus - Not yet observed. Tall, erect, white to violet flowers, narrow leaflets. From Hanford south, mostly in Oregon and Idaho.

Astragalus filipes - [sclerocarpus] Large shrubby, off-white to pale yellow aging to golden-tan flowers (often closed-looking). Narrow leaflets with short white hairs lying flat. Green calyx with dark hairs and short teeth. Often very floriferous with tall straight stems nearly vertical, but emerging from leaf axils. Drooping nearly straight seed pods, green with red edges. Common in Oregon, probably less so in Washington but widespread. https://www.inaturalist.org/observations/211953031. Distinguished from sclerocarpus: hairless pods, no violet on flower, not found on sand.

Astragalus inflexus - Purple flowered sprawling plant, compact raceme. Very long narrow calyx teeth, very wide leaflets, wooly to silky all over, curved erect seed pod. Mostly in SE Washington but present on Columbia Plateau as well, mostly right on the river. https://www.inaturalist.org/observations/211978029

Astragalus leibergii - [reventiformis] Medium sized, white flowers with large banner, stout straight upright flower stems. Calyx with short black to dark green hairs and moderately elongated teeth. Somewhat narrow leaflets. Seed pods erect, red to green with red speckles (later tan/brown), prominent longitudinal fold, fine extension at tip (all similar to reventiformis), but the base of the pod tapers to the pod stem, whereas reventiformis has a more abrupt pinch. If the calyx is still present there is a stalk (stipe) ABOVE the calyx connecting the fruit (https://www.inaturalist.org/observations/217316302). https://www.inaturalist.org/observations/213569452

Astragalus lentiginosus - Sprawling purple to pale flowered, at northern edge of range in WA but widespread on Columbia Plateau. Small compact racemes, leaflets wide with short silky hairs, green to rusty red calyx with short white or dark hairs and short to medium length pointed teeth. Flower looks rather closed (flag close to wings). Seed pod inflated with short pale hairs and green to yellow with red lines, blotches, or speckles. Pods: https://www.inaturalist.org/observations/169180855. Flowers: https://www.inaturalist.org/observations/162002302

Astragalus lyallii - [caricinus, spaldingii] Small sprawling plant on sandy soil, average width to wider leaflets, small off-white flowers with vertical purple stripes on banner sometimes with overall purple flush, short rounded wings, calyx with long narrow teeth, congested to loose raceme, silky white hairs all over, densest on raceme and calyx. Raceme axillary forming high on branched leaf-bearing stems. Seed pod with dense silky hairs. https://www.inaturalist.org/observations/213575999. Distinguished from spaldingii: location (partly), calyx teeth longer than flower tube.

Astragalus misellus - Not yet observed. Creamy white to pale yellow flowers.

Astragalus purshii - Abundant, small sprawling plant, purple to pale purple flowers usually sprawling on few-flowered racemes, extremely densely wooly/silky seed pods held to side. Easy to ID in flower or in seed.

Astragalus reventiformis - [leibergii] generally similar to A. leibergii but wider leaflets (about average while leibergii are usually narrower), longer calyx lobes, and usually taller. Endemic mostly to area between Yakima and Ellensburg in hills and dry montane areas. Barely overlapping range with leibergii, with the dividing line roughly from Cle Elum through Ellensburg to Hanford Reach. Pod with very short to no visible stalk (stipe) above calyx (https://www.inaturalist.org/observations/221925779). See leibergii for more comments. Comment from Aaron Liston at https://www.inaturalist.org/observations/211241784. Comment from mihail13 at https://www.inaturalist.org/observations/222053955. Pod base at https://www.inaturalist.org/observations/221925779.

Astragalus reventus - Erect white flower stems, average leaflets. Not yet observed, endemic to Blue Mountains.

Astragalus sclerocarpus - [filipes] Sprawling to semi-upright lanky plant with off-white flowers usually with pink to violet blush on wings and keel (usually darker especially tip), fading to yellowish. Narrow leaflets with fine white hairs lying flat. Green to pale calyx with dark hairs and short teeth. Drooping curved to nearly straight seed pod with very short hairs. On sand or very sandy soil. https://www.inaturalist.org/observations/212285319 Seed pods: https://www.inaturalist.org/observations/165801163. Distinguished from filipes: fine white hair on seed pods, usually some violet on flower, usually found on sandy soil. Seed pods mature to curved.

Astragalus spaldingii - [caricinus, lyallii] Not yet observed, small plant raceme elongated to congested and short, white flowers. Raceme densely long wooly, leaves and stems with abundant silky to wiry hairs. Calyx wooly/silky with very long teeth. Mostly in Channeled Scablands and southeast corner of WA. https://www.inaturalist.org/observations/215154432 (not mine). See caricinus and lyallii for differences.

Astragalus speirocarpus - Tightly curled seed pods. Usually medium-low shrubby looking with unusually wide leaflets and appressed white hairs. Calyx with black hairs and shortish teeth. Creamy white to pale yellow flowers usually with prominent purple markings on keel and base of wings. Wings seem to be more flared (angled laterally) than most Astragalus. https://www.inaturalist.org/observations/156340066

Astragalus succumbens - Often sprawling on sand with upright racemes. Wide leaflets with bristly looking edges. Flowers pink, white, or pale violet held above leaves in congested raceme, often appearing almost spherical. Calyx with stout hairs and long teeth. Seed pods erect with prominent furrow and shiny green, turning reddish brown. Common in sandy soils on southern Columbia Plateau. https://www.inaturalist.org/observations/208400719

Astragalus tweedyi - Not yet observed. Tall shrubby, white flowers. Erect green seed pod usually with red freckles. Almost all in eastern Columbia Transect and adjacent northern Oregon.

Astragalus whitneyi - Low sprawling plant, purple or white flowers in few-flowered compact raceme, fairly wide leaflets, on rocky to very rocky soil. Calyx moderately white hairy with medium sized pointed teeth and often dull red. Keel more beaked than most Astragalus, often protruding well above the wings. Leaflets medium wide, somewhat wooly or with appressed white hairs. Seed pod very distinctive, inflated with red markings. Usually in lower eastside mountains in WA, rocky soil. Seed pod: https://www.inaturalist.org/observations/127128415. Flower: https://www.inaturalist.org/observations/221614523.

Posted on Μάιος 05, 2024 1030 ΜΜ by jhorthos