Astragalus Identification (Washington State)
Other plants that can be confused with in square brackets (Washington State range only)
Astragalus caricinus - Small to medium sized semi-erect plant with small tan flowers. Silky hairy all over especially raceme and calyx, high axillary floral raceme, medium small with smallish light tan to off-white flowers. Calyx silky hairy with long narrow teeth. Leaf shape about average. Small silky hairy seed pod (but nowhere near purshii). Often in sandy soil. https://www.inaturalist.org/observations/212263702
Astragalus collinus - Not yet observed. Tall, semi-sprawling, tall erect yellow flowered spike. Found in Okanogan (north central) and southeast corner of state. https://www.inaturalist.org/observations/215849553
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 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 - Medium sized, white flowers, stout straight upright flower stems. Calyx with short black to dark green hairs and moderately elongated teeth. Average to slightly narrow leaflets. Seed pods erect, red to green with red speckles, prominent longitudinal fold, fine extension at tip. 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, leaves 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 and green to yellow with red lines or speckles. Pods: https://www.inaturalist.org/observations/169180855. Flowers: https://www.inaturalist.org/observations/162002302
Astragalus lyallii - [spaldingii] Small sprawling plant, fairly wide 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 - Not yet observed, generally similar to A. leibergii but wider leaflets (about average). Endemic mostly to area between Yakima and Ellensburg in hills. Comment from Aaron Liston at https://www.inaturalist.org/observations/211241784
Astragalus reventus - 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. Narrow leaflets. 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
Astragalus spaldingii - [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)
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 greed 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. Calyx moderately white hairy with medium sized pointed teeth and often dull red. Leaves 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. https://www.inaturalist.org/observations/127124906 Seed pod: https://www.inaturalist.org/observations/127128415
