2010 Kansas Wildflower of the Year
Catclaw Sensitive Brier
CATCLAW SENSITIVE BRIER Schrankia nuttallii
DERIVATION OF NAMES
"Catclaw" - refers to the hooked prickles on the stems and the prickly pods; "sensitive" - refers to the sensitivity flower ball (actual) and response of leaves to touch; ''brier'' - refers to the prickly nature of the plant; "Schrankia" - named for Franz von Paula von Schrank, a German botanist of the late eighteenth and early nineteenth centuries; "nuttallii" - named for Thomas Nuttall, a nineteenth century American naturalist.
OTHER COMMON NAMES
Bashful brier, sensitive brier, sensitive rose, shame vine.
SCIENTIFIC NAMES (SYNONYMS)
Mimosa family (Mimosaceae). This family is related to the bean family and also has compound leaves and a pod that opens on two sides (a legume). However mimosas have small flowers with long exserted filaments, the flowers densely clustered in a ball.
Catclaw sensitive brier has attractive fine-cut foliage, an interesting response by the leaf to touch and dainty yellow-dotted pink flower balls. The stems are spreading and vine-like, 1 to 7 feet long; but the plant is seldom more than 1 foot high. The stems are strongly ribbed and have many recurved prickles which can catch on clothes or skin. The leaves are bipinnately compound, with a central stalk to which are attached four to eight pairs of leaflet- bearing stalks. Each leaflet-bearing stalk has nine to fifteen pairs of small elliptic pointed leaflets. When touched or shaken, these leaves fold and droop. The leaves also fold at night or on dark cloudy days. Catclaw sensitive brier blooms from early June to July, or later if conditions are favorable. The inflorescence is a dense fluffy ball of small pink flowers with protruding long pink filaments supporting small yellow anthers. The flower balls are 3/4 to 1 1/2 inches in diameter and are supported on moderately long stalks (peduncles) from the axils of leaves near the ends of stems.
GROWING CHARACTERISTICS AND MANAGEMENT
Catclaw sensitive brier is a perennial. A number of sprawling branched stems arise from a woody crown and become somewhat woody as they mature. The bipinnately compound leaves are arranged alternately. The plant has a deep root. It does not spread aggressively. Young plants will usually bloom in their second season of growth.
The seed has been used as a laxative (Stubbendieck and Conard 1989).
RELATIONS TO ANIMALS
Livestock, deer and wild turkeys eat the foliage of this plant, particularly the tender new growth. It is a nutritious high protein food. This species decreases under heavy grazing. Upland birds and rodents eat the seeds. Insect larvae eat many of the seeds in the pods.
SEEDS AND FRUIT
The fruits are slender brown dry prickly pods (legumes) 1 to 5 inches long with many seeds. The pod opens explosively throwing many of its seeds. The seeds are brown, smooth, somewhat irregular, 4-sided but slightly flattened and approximately 1/8 inch long. The fruits should be collected as soon as they dry and before they open, usually mid-July and later. The seeds are easily removed from the pods by putting the pods in a sack and shaking or pounding on them. The pieces of pods can be separated out with the use of sieves.
Without mechanical scarification, germination is very low. With scarification using medium sandpaper, we have gotten an average germination of 49% (28% - 68%).
Scarified seeds can be planted in the field or seedlings can be started indoors. The proper Rhizobium inoculant strain should be used if soil in which this species has grown is not available. Seedlings grow well in the greenhouse and have few problems.
The pair of medium-sized cotyledons are thick, widest near the base, 30-40% longer than wide, and are borne on short stalks. Each cotyledon is notched at the point of attachment to its stalk. The outside comers at the base of the cotyledons are pointed backwards. The true leaves arise one at a time on stalks (petioles) from an upright growing stem that is much narrower than the stem below the cotyledons. There are stipules at the base of the leaf stalks (petioles). The first true leaf is pinnately compound with three to five pairs of leaflets. The second true leaf is bipinnately compound having two leaflet-bearing stalks with five pairs of leaflets on each. Succeeding leaves get more and more leaflets.
Salac, et al. (1978) stated that this species can be propagated by stem cuttings.
Catclaw sensitive brier is found throughout Kansas except along the far western border. It grows in the plains region from central South Dakota to Texas but is rare or absent in the western part. Its range extends east to lllinois and Alabama.
Catclaw sensitive brier is found in nearly all prairie types and in open woods. It is also found in some disturbed sites such as roadsides. It is particularly common on sandy or gravelly soils.
Salac, S.S., P.N. Jensen, JA. Dickerson and R. W. Gray, Jr. 1978. Wildflowers for Nebraska Landscapes. Lincoln, NE: The Agricultural Experiment Station, University of Nebraska - Lincoln, 28 pp.
Stubbendieck, James and E1veme C. Conard. 1989. Common Legumes of the Great Plains. lincoln, NE: University of Nebraska Press, xxii + 330 pp.
Growing Native Wildflowers by Harder and Platt. page 91.15
See also an article in the Fall 2009 newsletter.
Schrankia nuttallii has be renamed to Mimosa nuttallii.