Mirabilis hirsuta (Pursh) MacM. 



HAIRY FOUR-O'CLOCK 

 Four-0' Clock Family (Nyctaginaceae) 



CONSERVATION STATUS 



U. S. Fish and Wildlife Service: None 



Bureau of Land Management: Watch 



Montana Natural Heritage Program: It was ranked G5 SI on the most recent state list 

 (Heidel 1 997); demonstrably secure globally, but may be critically imperiled in Montana due 

 to extreme rarity. During the 1 997 field season, new information was gathered that provided 

 a basis for changing its rank to SU; status unresolved as vulnerable, no longer tracked as a 

 state species of special concern, moved instead to the watch list. 



DESCRIPTION: Hairy four-o'clock is a perennial herb from a stout taproot topped by a branched 

 root crown. Stems are usually unbranched and erect, stand 2-12 dm tall, and lower stems are densely- 

 covered by long, multicellular hairs. The opposite leaves lack, or have short (< 5 mm) petioles, and 

 have blades, 2-12 cm long, which are variable in shape and vestiture, ranging fi-om lance to egg to 

 diamond shaped, and from long to short hairy or rarely nearly hairless. Five lobed, greenish to 

 purplish tinged, calyx-like involucres, 4-10 mm long, are borne terminally and in leaf axils. Each 

 involucre encloses usually three flowers. The flowers lack corollas but have pale pink to purplish 

 red, tubular corolla-like calyces, 8-12 mm long, and 3-5 exerted stamens. As fruits mature, the 

 calyces harden around them to form a five ribbed, roughened or tuberculate, olive to brown, densely 

 to sparsely hairy accessory fhiit, 4-5 mm long. Flowering in July-early August. 



Mirabilis hirsuta is distinguished ft-om other Montana species in the genus by having lower stems 

 hairy with long multicellular hairs and leaves which lack or have only short petioles. Mature fi-uits 

 are desirable for positive identification. 



GEOGRAPHICAL DISTRIBUTION 



Global distribution: Wisconsin to Manitoba 

 and eastern Montana, south to Missouri, 

 Louisiana, Texas, and New Mexico, apparently 

 rare across much of it range (Great Plains Flora 

 Association 1986). 



Montana distribution: Carter, Choteau, and 

 Sheridan counties. 



Mirabilis hirsuta 

 Hairy Four-O'Clock 



Natural HerttaBa Program May 1998 



Carter County distribution: There is only one 

 record fi-om the county, a collection in 1973, from 

 Medicine Rocks State Park. 



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