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Photo is of parent taxon

Moab milkvetch

coal-cliffs milkvetch, Colton's milkvetch

Habit Plants clump-forming, 10–75 cm, strigulose, canescent, cinereous, or greenish cinereous; from subterranean or branched, superficial caudex.
Stems

strigulose, cinereous, greenish cinereous, or canescent;

from subterranean caudex.

erect or ascending, strigulose, canescent, cinereous, or greenish cinereous.

Leaves

odd-pinnate, (2–)3–9 cm;

leaflets (5–)9–17(or 19), blades oblong, cuneate-oblong, or ovate, (3–)5–20 mm, apex obtuse, truncate, or retuse, surfaces brighter green and, usually, less densely pubescent abaxially;

leaflets jointed or joint obscure in distal ones.

dimorphic, some unifoliolate distally and reduced to phyllodia, continuous with rachis, 2–10 cm;

stipules distinct throughout, 1–7 mm, papery at proximal nodes, herbaceous at distal nodes;

leaflets (1 or)3–19, blades linear, oblong, cuneate-oblong, or ovate, (3–)4–20 mm, apex acute, obtuse, truncate or retuse, surfaces strigose;

terminal leaflet decurrent distally, not jointed to rachis.

Racemes

(6–)10–30-flowered.

(2–)5–30-flowered, flowers spreading-declined;

axis 3–20 cm in fruit;

bracts 0.5–3.2 mm;

bracteoles 0.

Peduncles

(4–)6.5–21 cm.

erect or incurved-ascending, (4–)6.5–30 cm.

Pedicels

0.8–2.5 mm.

Flowers

12–19 mm;

calyx purplish, cylindric, 4.5–8 mm, strigose, tube 4–6.7 mm, lobes broadly subulate, 0.6–2.3 mm;

corolla pink-purple;

banner recurved through 35–50°;

keel 9–13 mm, apex bluntly or sharply deltate.

Legumes

19–35 × (3–)3.5–6 mm;

stipe 5–11 mm.

pendulous, green or reddish becoming stramineous, straight or gently decurved, oblong to oblanceoloid, strongly compressed, flattened laterally, 19–35 × (3–)3.5–6 mm, stiffly papery, glabrous;

stipe 4–11 mm.

Seeds

14–20.

Astragalus coltonii var. moabensis

Astragalus coltonii

Phenology Flowering Apr–Jun.
Habitat Pinyon-juniper and mountain brush communities.
Elevation 1400–2600 m. (4600–8500 ft.)
Distribution
from FNA
AZ; CO; NM; UT; WY
[BONAP county map]
from USDA
w United States
[WildflowerSearch map]
[BONAP county map]
Discussion

Variety moabensis is primarily in the Four Corners region of Apache and Navajo counties in northeastern Arizona, Dolores, Mesa, Montezuma, and Montrose counties in southwestern Colorado, San Juan County in northwestern New Mexico, and Grand and San Juan counties in southeastern Utah. The populations in Sweetwater and Uinta counties in southwestern Wyoming may represent recent introductions due to livestock transport.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Varieties 2 (2 in the flora).

R. C. Barneby (1964) aligned Astragalus coltonii with A. filipes in Homalobus or the equivalent sect. Homalobi. Although A. filipes is similar with its compressed and stipitate fruit, the stipules are fundamentally different. P. A. Rydberg (1929) and M. E. Jones (1923) described the stipules of A. coltonii as connate; proximal stipules do form a bidentate, more or less amplexicaul sheath, but the interpretation is not strictly correct. The stipules are united by adherence to a vestigial petiole and are consistent with all genuine sect. Lonchocarpi and not like those in A. filipes, which are united by their contrapetiolar margins.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Leaves odd-pinnate or distalmost unifoliolate; leaflets (1 or)3–11, terminal leaflet each confluent with rachis.
var. coltonii
1. Leaves odd-pinnate; leaflets (5–)9–17(–19), jointed or joint obscure distally.
var. moabensis
Source FNA vol. 11. FNA vol. 11.
Parent taxa Fabaceae > subfam. Faboideae > Astragalus > sect. Lonchocarpi > Astragalus coltonii Fabaceae > subfam. Faboideae > Astragalus > sect. Lonchocarpi
Sibling taxa
A. coltonii var. coltonii
A. accidens, A. accumbens, A. ackermanii, A. acutirostris, A. adanus, A. aequalis, A. agnicidus, A. agrestis, A. albens, A. albulus, A. allochrous, A. alpinus, A. altus, A. alvordensis, A. amblytropis, A. americanus, A. amnis-amissi, A. amphioxys, A. ampullarioides, A. ampullarius, A. andersonii, A. anisus, A. anserinus, A. applegatei, A. aquilonius, A. aretioides, A. argophyllus, A. aridus, A. arizonicus, A. arrectus, A. arthurii, A. asclepiadoides, A. asotinensis, A. asymmetricus, A. atratus, A. atropubescens, A. atwoodii, A. austiniae, A. australis, A. barnebyi, A. barrii, A. beathii, A. beatleyae, A. beckwithii, A. bernardinus, A. bibullatus, A. bicristatus, A. bisulcatus, A. bodinii, A. bolanderi, A. bourgovii, A. brandegeei, A. brauntonii, A. brazoensis, A. breweri, A. californicus, A. callithrix, A. calycosus, A. camptopus, A. canadensis, A. caricinus, A. casei, A. castaneiformis, A. castetteri, A. ceramicus, A. cerussatus, A. chamaeleuce, A. chamaemeniscus, A. chinensis, A. chloödes, A. chuskanus, A. cibarius, A. cicer, A. cimae, A. claranus, A. clevelandii, A. cliffordii, A. cobrensis, A. coccineus, A. collinus, A. columbianus, A. concordius, A. congdonii, A. conjunctus, A. consobrinus, A. contortuplicatus, A. convallarius, A. cottamii, A. crassicarpus, A. cremnophylax, A. cronquistii, A. crotalariae, A. curtipes, A. curvicarpus, A. cusickii, A. cutleri, A. cyaneus, A. cymboides, A. deanei, A. debequaeus, A. desereticus, A. desperatus, A. deterior, A. detritalis, A. diaphanus, A. didymocarpus, A. distortus, A. diversifolius, A. douglasii, A. drabelliformis, A. drummondii, A. duchesnensis, A. eastwoodiae, A. egglestonii, A. emoryanus, A. endopterus, A. ensiformis, A. episcopus, A. equisolensis, A. eremiticus, A. ertterae, A. eucosmus, A. eurekensis, A. eurylobus, A. falcatus, A. feensis, A. filipes, A. flavus, A. flexuosus, A. fucatus, A. funereus, A. gambelianus, A. geyeri, A. gibbsii, A. giganteus, A. gilensis, A. gilmanii, A. gilviflorus, A. glycyphyllos, A. gracilis, A. grayi, A. gypsodes, A. hallii, A. hamiltonii, A. harrisonii, A. heilii, A. henrimontanensis, A. holmgreniorum, A. hoodianus, A. hornii, A. howellii, A. humillimus, A. humistratus, A. hyalinus, A. hypoxylus, A. inflexus, A. insularis, A. inversus, A. inyoensis, A. iodanthus, A. iodopetalus, A. iselyi, A. jaegerianus, A. jejunus, A. johannis-howellii, A. kelseyae, A. kentrophyta, A. kerrii, A. knightii, A. laccoliticus, A. lancearius, A. laxmannii, A. layneae, A. leibergii, A. lemmonii, A. lentiformis, A. lentiginosus, A. leptaleus, A. leptocarpus, A. leucolobus, A. limnocharis, A. lindheimeri, A. linifolius, A. loanus, A. lonchocarpus, A. lotiflorus, A. lutosus, A. lyallii, A. macrodon, A. magdalenae, A. malacoides, A. malacus, A. megacarpus, A. michauxii, A. microcymbus, A. microcystis, A. microlobium, A. micromerius, A. miguelensis, A. minthorniae, A. misellus, A. miser, A. missouriensis, A. moencoppensis, A. mohavensis, A. mollissimus, A. molybdenus, A. monoensis, A. montii, A. monumentalis, A. mulfordiae, A. multiflorus, A. musiniensis, A. naturitensis, A. neglectus, A. nelsonianus, A. neomexicanus, A. nevinii, A. newberryi, A. nidularius, A. nothoxys, A. nudisiliquus, A. nutans, A. nutriosensis, A. nuttallianus, A. nuttallii, A. nutzotinensis, A. nyensis, A. obcordatus, A. obscurus, A. oniciformis, A. oocalycis, A. oocarpus, A. oophorus, A. oreganus, A. osterhoutii, A. oxyphysus, A. pachypus, A. palmeri, A. panamintensis, A. pardalinus, A. parryi, A. pattersonii, A. pauperculus, A. paysonii, A. peckii, A. pectinatus, A. perianus, A. phoenix, A. pictiformis, A. pinonis, A. piscator, A. piutensis, A. plattensis, A. platytropis, A. polaris, A. pomonensis, A. porrectus, A. praelongus, A. preussii, A. proimanthus, A. proximus, A. pseudiodanthus, A. pterocarpus, A. pubentissimus, A. pulsiferae, A. puniceus, A. purshii, A. pycnostachyus, A. racemosus, A. rafaelensis, A. rattanii, A. ravenii, A. recurvus, A. reflexus, A. remotus, A. reventiformis, A. reventus, A. riparius, A. ripleyi, A. robbinsii, A. rusbyi, A. sabulonum, A. sabulosus, A. salmonis, A. saurinus, A. scaphoides, A. schmolliae, A. sclerocarpus, A. scopulorum, A. sepultipes, A. serenoi, A. sericoleucus, A. serpens, A. sesquiflorus, A. sheldonii, A. shevockii, A. shortianus, A. siliceus, A. simplicifolius, A. sinuatus, A. solitarius, A. sophoroides, A. soxmaniorum, A. spaldingii, A. sparsiflorus, A. spatulatus, A. speirocarpus, A. straturensis, A. striatiflorus, A. subcinereus, A. subvestitus, A. succumbens, A. tegetarioides, A. tener, A. tennesseensis, A. tephrodes, A. terminalis, A. tetrapterus, A. thurberi, A. tibetanus, A. tidestromii, A. tiehmii, A. titanophilus, A. toanus, A. toquimanus, A. tortipes, A. traskiae, A. tricarinatus, A. trichopodus, A. tridactylicus, A. troglodytus, A. tweedyi, A. tyghensis, A. umbellatus, A. umbraticus, A. uncialis, A. utahensis, A. vaccarum, A. vallaris, A. vexilliflexus, A. villosus, A. wardii, A. waterfallii, A. webberi, A. welshii, A. wetherillii, A. whitneyi, A. williamsii, A. wingatanus, A. wittmannii, A. woodruffii, A. wootonii, A. wrightii, A. xiphoides, A. yoderwilliamsii, A. zionis
Subordinate taxa
A. coltonii var. coltonii, A. coltonii var. moabensis
Name authority M. E. Jones: Contr. W. Bot. 8: 11. (1898) — (as coltoni) unknown
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