The Rosinweed (Silphium) Genus: Compass plant, Cup plant, Prairie dock and Rosinweed

April 9th, 2020

(Silphium laciniatum, S. perfoliatum, S. terebinthinaceum and S. integrifolium)

This genus of herbaceous perennial plants that are grouped in the Aster family and the sunflower tribe and are found from central eastern Canada to the southeastern United States. This genus is usually referred to as the rosinweeds.
There are several species in this genus each having a specific habitat but the genus is representative of a broad set of characteristics.

Physical description

These plants grow to 8 in. to more than 8 ft tall, with yellow (rarely white) flowerheads that resemble sunflowers. They all have similar characteristics, however, on some the leaves are larger; on some the leaves are indented; on some the plant is far taller than others, etc. The base of each oval cup plant (Silphium perfoliatum) leaf surrounds the square stem and may hold water. Compass plant (S. laciniatum), is a prairie plant with large, deeply cut, lance-shaped leaves. It may grow to about 12 feet and has a tall flower stalk with solitary large flowers.

habitat

Each of the above species are easily grown in average, medium, well-drained soils in full sun. They all tolerate poor soils.

photos

Uses

All members of this genus provide good height for the rear of the garden border. Also, they are excellent for naturalizing in cottage gardens, wildflower gardens or native plant gardens. In addition, these flowers have very sturdy stems making them ideal as cut flowers for displays within the home or office.

protection status

None of these species are protected by Federal or international agencies.

interesting information

The genus name Silphium comes from the Greek name silphion, used to refer to a North African resin bearing plant.

These four species are currently available at Reflection Riding Arboretum and Nature Center.

Of the 23 species found in this genus, some have opposite leaf arrangement, some have alternate leaf arrangement, and some have neither but rather whorled leaves. Leaf arrangement is thought to be a characteristic that separated various plants into at least species or genera — not the Silphium genus.

about professor charlie belin

Charlie is a retired professor and Biological Oceanographer. He taught five courses in the University of Georgia System for many years from his home base in Savannah, Georgia.  

Charlie loves hiking at Reflection Riding, teaching children about the ecology of the area, and interacting with the Reflection Riding staff. They are GREAT!

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Posted by Charlie Belin  | Category: native plants
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