The Skullcaps
Scuttelaria spp.
Family: Lamiaceae
The skullcaps belong to a large genus of over 300 species that occur nearly worldwide. There are 4 species native to Arizona and more in nearby states.
Skullcaps are used in traditional medicine, such as in traditional Chinese medicine. The root of Scutellaria baicalensis – a common component of many preparations – is marketed in volumes that have led to the overexploitation of the wild plant. Its rarity has led to an increase in price, and encouraged the adulteration of the product with other species of Scutellaria.
Today skullcap is still a popular medicinal herb. It is widely available as a commercial product used in western herbalism. Growing your own plants for use can help decrease the economic pressures that impact wild plants.
Most skullcaps have similar chemistry and with varying results can be substituted for the skullcaps on the market.
Most of the species we grow in the southwest are probably hummingbird pollinated. Many moth species use them as larval hosts.
Photo of Scuttelaria potosina by José G. Flores Ventura, iNaturalist
The generic name is derived from the Latin scutella, meaning "a small dish, tray or platter", or "little dish", referring to the shape of the calyx.
Paper Bag Bush
Scutellaria mexicana
Probably the strangest and most xeric (dry growing) of the Scutellaria species. Rounded shrubby perennial growing to about 3’ though often smaller. Purple and white flowers appear appear April through June followed by little paper bag-like fruits that may persist all the way into winter. Leaves are drought and cold deciduous.
Full sun, moderate to low water with good drainage, hardy to about 15°F.
Formerly known as Salazaria mexicana. The old genus, Salazaria, is named after Don Jose Salazar (1823-1892), Mexican commissioner on the Boundary Survey, and the species, mexicana, means of or from Mexico.
A variety of habitat types across their entire range; foothills and washes in creosote-bush communities, mostly deserts but reaching lower margins of the pinyon-juniper zones below 3000 ft. in western Arizona, southwest California, southern Nevada, and a small disjunct population in west Texas (Brewster County). Also found in Baja California and northern Mexico.
Mexican Skullcap
Scutellaria potosina
Herbaceous perennial growing to about 2x2’. Blue to purple flowers April through August.
Part sun best, moderate to regular water, hardy to probably about 15°F. Cut back plants as needed.
The species name, potosina, refers to San Luis Potosí, Mexico, where this plant is found growing naturally.
Rocky areas, washes and sandy areas, 2,500 to 5,500 ft. in Arizona, New Mexico, and into northern Mexico.
‘Dark Violet’ Skullcap
Scutellaria resinosa x S. suffrutescens
Herbaceous perennial growing to about half a foot tall, and about a foot wide. Purple flowers April through August.
Part sun best, moderate to regular water, cold hardy to temperatures between -10° and -20° F. Cut back plants as needed.
This is a hybrid plant and does not occur in nature.
Pink Skullcap
Scutellaria suffrutescens
Perennial, evergreen plant growing usually under a foot tall but spreading about 2, rarely 3’. Pink flowers spring through fall.
Full to part sun, moderate water, hardy to 0°F. Cut back occasionally.
The species name, suffrutescens, means subshrub, referring to the smaller stature of the plant.
From limestone ledges in Tamaulipas, Mexico.
Photo by Alejandro Huereca Delgado, iNaturalist
Starrfire Skullcap
Scutellaria sp.
Perennial plant growing less than a foot high but spreading to about 2-3’. Red flowers spring through fall.
Full to part sun, moderate water, hardy to 10°F. This plant really needs extremely good drainage. It does well in pots.
Found by Greg Starr in the Barranca de Tolontogo, Hildago, Mexico on a limestone roadcut. This plant is likely a new species and is waiting to be described/named.