Archive image from page 81 of Botanical and vegetation survey of. Botanical and vegetation survey of Carter County, Montana, Bureau of Land Management-administered lands D4B7AF30-6FF2-4017-ADC9-7C50A7256521 Year: 1998 Asclepias stenophylla A. Gray NARROWLE AF MILKWEED Milkweed Family (Asclepiadaceae) CONSERVATION STATUS Fish and Wildlife Service: None. Bureau of Land Management: Watch. Montana Natural Heritage Program: G4G5 SI; The species may be demonstrably secure throughout its range, but may be critically imperiled in Montana where it is extremely rare. DESRIPTION: Narrow-leaved mil
Archive image from page 81 of Botanical and vegetation survey of. Botanical and vegetation survey of Carter County, Montana, Bureau of Land Management-administered lands D4B7AF30-6FF2-4017-ADC9-7C50A7256521 Year: 1998 Asclepias stenophylla A. Gray NARROWLE AF MILKWEED Milkweed Family (Asclepiadaceae) CONSERVATION STATUS Fish and Wildlife Service: None. Bureau of Land Management: Watch. Montana Natural Heritage Program: G4G5 SI; The species may be demonstrably secure throughout its range, but may be critically imperiled in Montana where it is extremely rare. DESRIPTION: Narrow-leaved milkweed is a perennial herb that grows from a stout underground rootstock. The stems, usually a single or pair per plant, are decumbent or upright, usually unbranched, 2-8 dm (8-30 in) long, and are filled with milky sap. The leaves are borne alternately to sub-oppositely along the stem and are linear shaped and 8-18 cm (3-7 in) long, by 1-5 mm ( in) wide. The foliage is moderately to sparsely hairy. Umbrella-shaped clusters of 10-25 fiowers are nearly stemless in the leaf axils of the upper half of the stem. Each greenish-white to yellow fiower is 7-9 mm long and is borne on a hairy pedicel up to 1 cm long. Flowers have 5 reflexed corolla lobes and 5 erect ihoodsi which are tri-lobed at the tip and surround a central column. The erect, spindle-shaped fruits are 9-12 cm (4-5 in) long and less than 1 cm wide. Each fruit contains numerous seeds which have white tails about 3 cm (1 in) long. Flowering in June-early July. Both whorled milkweed {Asclepias verticillata) and plains milkweed {A. pumila) also have narrow leaves but they both have more crowded often filiform leaves usually less than mm wide and uniformly short in length. The flower clusters are borne on stalks that are greater than 5 mm long rather than being nearly stemless in the leaf axils. The leaves of green milkweed {A. viridiflora), a highly variable species, are sometimes linear, but the hoods of the flowers
Size: 1892px × 1057px
Photo credit: © Actep Burstov / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: 1998, archive, book, bookauthor, bookpublisher, booksubject, bookyear, botany, cooper_stephen_v, drawing, heidel_bonnie_l, helena_mt_montana_natural_heritage_program, historical, history, illustration, image, montana_natural_heritage_program, page, picture, print, rare_plants, reference, united_states_bureau_of_land_management, vanderhorst_james_p, vintage, zimmermann_a_albrecht_b_1860
