Senna hirsuta v glaberrima, Woolly Senna, Southwest Desert Flora

Senna hirsuta v glaberrima, Woolly Senna

Woolly Senna has yellow to deep orange-yellow irregular flowers with prominent darker brown veins as the flower matures. Senna hirsuta var. glaberrima

Woolly Senna is a forb/herb, subshrub, shrub or even a tree; the foliage is considered foul smelling to some; a key characteristic is that this species is mostly without pubescence or glabrous. Senna hirsuta var. glaberrima

Woolly Senna prefers to grow along streams and washes and south facing slopes. It is found between 2,500 to 5,500 feet (762 - 1,676 m) elevation. Senna hirsuta var. glaberrima

Woolly Senna is relatively rare in the United States where it is found only in southern Arizona and southwest New Mexico. Plants bloom from July to September. Senna hirsuta var. glaberrima

Scientific Name: Senna hirsuta var. glaberrima
Common Name: Woolly Senna

Also Called: Sicklepod, Slimpod Glaberrima Senna, Slimpod Senna, Stinking Cassia, Woolly Wild Sensitive Plant, Woolly Wild Sensitive-plant

Family: Fabaceae or Leguminosae Family

Synonyms: (Cassia leptocarpa, Cassia leptocarpa var. glaberrima, Cassia gooddingii, Ditremesa glaberima)

Status: Native

Duration: Perennial

Size: Up to 3 feet (1 m) or more.

Growth Form: Woolly Senna is a forb/herb, subshrub, shrub or even a tree; the foliage is considered foul smelling to some; a key characteristic is that this species is mostly without pubescence or glabrous; stems with small appendages or stipules.

Leaves: Woolly Senna has green pinnately compound leaves with stipules at the base; the leaves have large linear leaflets.

Flower Color: Woolly Senna has yellow to deep orange-yellow irregular flowers with prominent darker brown veins as the flower matures; the fruit is a linear pod that turns brown with maturity.

Flowering Season: July to September.

Elevation: 2,500 to 5,500 feet (762 - 1,676 m).

Habitat Preferences: Along streams and washes, south facing slopes.

Recorded Range: Relatively rare in the United States, Woolly Senna is found only in southern Arizona and southwest New Mexico. It is also native to Mexico, South America and the West Indies. The exact origin may be unknown.

North America & US County Distribution Map for Senna hirsuta var. glaberrima as Senna hirsuta.

Wetland Indicator: In North America Senna hirsuta has the following wetland designations;

Arid West, FACU

Caribbean, FAC

Western Mountains Valleys, and Coast, FACU

FACU = Facultative Upland, usually occur in non-wetlands, but may occur in wetlands.

FAC = Facultative, occur in wetlands and non-wetlands.

Invasive/Noxious Weed Information: Unknown
Threatened/Endangered Information: Unknown
U.S. Weed Information: Unknown

According to The Global Compendium of Weeds; Senna hirsuta (Fabaceae) lists Senna hirsuta as an "environmental weed, garden thug, naturalised, weed".

Genus Information: In North America, USDA Plants Database lists 27 native species and 14 introduced species for Senna. Worldwide, World Flora Online includes 362 accepted species names for the genus. The Plant List lists 351 species for Senna.

The genus Senna was published in 1754 by Philip Miller (1691-1771).

In the Southwestern United States: Arizona has 14 species of genus, California and New Mexico each have 11 species, Nevada has 3 species, Texas has has 23 species and Utah has 0 species. Data approximate, subject to revision.

Several members of the genus Senna have been re-classified from Cassia.

There are 3 varieties in Senna hirsuta in the United States;

Senna hirsuta var. glaberrima, Woolly Senna (AZ, NM only)

Senna hirsuta var. hirsuta, Woolly Senna

Senna hirsuta var. leptocarpa

Comments: There is slight information published or on-line, available for Woolly Senna in general and variety "hirsuta". The type specimen for Cassia leptocarpa var. glaberrima was collected from southern Arizona; the type specimen for the original classification of Cassia Gooddingii was collected from the Huachuca Mountains (Goodding 2431).

Also see in Southwest Desert Flora; Twinleaf Senna, Senna bauhinioides, Coves' Cassia, Senna covesii and Baja California Senna, Senna purpusii.

Importance to Wildlife, Birds and Livestock Woolly Senna, Senna hirsuta has attractive flowers, the flowers, their seeds and plants may be visited by hummingbirds and/or small mammals including rodents and granivorous birds in search of food, nectar and protection through cover.

Beneficial Value to Butterflies, Honey Bees and Insects Woolly Senna, Senna hirsuta has attractive flowers, the flowers and their plants may be visited or used by butterflies, moths, flies, honeybees, native bees and other insects in search of nectar, food or shelter and protection.

In addition, according to the Arizona Sonora Desert Museum, "Plant Care Information" notice, Sulphur, Hairstreak and Blue butterflies are attracted to all of the Sennas.

****Special Value to Bumble Bees**** According to The Xerces Society for Invertebrate Conservation or other source, Woolly Senna, Senna hirsuta, is recognized by pollination ecologists as attracting large numbers of Bumble Bees. Click here for more information on their Pollinator Conservation Program.

Etymology: The genus “Senna” is from the Arabic name Sana.

The genus Senna was published in 1754 by Philip Miller (1691-1771).

The species epithet “hirsuta” (hirsu'ta:) means covered with hair.

The variety epithet “glaberrima” (glaberri'ma:) means completely glabrous.

Ethnobotany - Native American Ethnobotany; University of Michigan - Dearborn Unknown.