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Plant Profile

Ruth's Silk-grass (Pityopsis ruthii)

This shot shows a mass of Ruth's golden aster flowers. Photo Credit: Rob Gardner

Global Rank: G1 - Critically Imperiled
Legal Status: Federally Endangered
Family: Asteraceae
State: TN
Nature Serve ID: 153865
Lifeform: Forb/herb
Date Inducted in National Collection: 04/04/1991

Description:

Ruth's Golden-aster is an herbaceous tufted perennial that has slender stoloniferous rhizomes. Its leaves are numerous, cauline, linear, and silvered with long apressed hairs. The inflorescence is comprised of one to several heads of yellow composite flowers in a cyme. This southeastern Tennessee endemic has only two known populations. Ruths golden-aster grows in the crevices of boulders in the natural flood zone of the Hiwassee and Ocoee Rivers, where upstream activities have significantly altered the riparian habitat. Threats include disruption of natural flooding cycles by dam construction, degradation of water quality by mining activity, toxic chemical spills, and trampling by recreational boaters. Ruths golden-aster populations have historically been maintained on these riverbanks due to periodic high water flows that remove competing vegetation. On the Hiwassee River, the prevention of flooding has caused increased competition and invasion by shade-tolerant species. On the Ocoee River, the increased frequency and decreased magnitude of flooding events (water releases for hydropower and recreational activities) has prevented recruitment of new plants. The protection and recovery of Pityopsis ruthii is currently overseen jointly by a number of organizations.

Where is Ruth's Silk-grass (Pityopsis ruthii) located in the wild?

Habitat:

Found in soil-filled cracks of phyllite or graywacke boulders in riparian areas/rocky river shoals which experience periodic flooding and scouring. (USFWS 1992)

Distribution:

Polk County, Tennessee (USFWS 1992)

States & Provinces:

Ruth's Silk-grass can be found in Tennessee

Which CPC Partners conserve Ruth's Silk-grass (Pityopsis ruthii)?

North Carolina Botanical Garden

Conservation Actions

Michael Kunz

01/12/2023

NCBG staff made two collecting trips to TN in the fall of 2022 to collect seeds of Pityopsis ruthii. The purpose of the collection was to update aging collections stored in the NCBG seed bank and to collect fresh seed material for the IMLS Seed Longevity study. We successfully collected seed from the extent of the population and split the collection for backup storage at NLGRP.

Center for Plant Conservation

08/19/2021

In 2021, CPC contracted North Carolina Botanical Garden to recollect seed from a population currently held in long term orthodox seed storage as part of an IMLS-funded seed longevity experiment. The National Laboratory for Genetic Resources Preservation will evaluate how germination tested viability and RNA Integrity of seed lots decline over time in storage.

Nature Serve Biotics

05/02/2017

A very localized endemic of southeastern Tennessee. The only two populations known are on short reaches of rivers which have been dammed, essentially eliminating natural water flows. On one of the rivers, annual scouring no longer occurs and shade-tolerant species are rapidly invading and replacing Pityopsis ruthii. On the other, whitewater recreation related impacts are a threat.

01/01/2010

Succession/competition (Hiwassee population) Construction and repair of highways Competition from woody and herbaceous plants Water quality degradation Alterations in water levels and flow regimes Toxic chemical spills Trampling (due

01/01/2010

Known from 2 populations in Polk Co., TN: Ocoee River with exactly 593 individuals, and Hiwassee with ca. 10,000-15,000 individuals (USFWS 1992)

01/01/2010

M.B. Cruzan at the University of Tennessee at Knoxville studied the long-term demographic trends in Pityopsis ruthii. (Cruzan 1996)

01/01/2010

None known.

01/01/2010

Surveys for additional occurrences on other rivers in TN and in southwestern NC Re-introduction research Continuing protection of populations from trampling Plans for mitigating effects of dams and mining activities Pollination studies Fruit dispersal and recruitment of seedlings

01/01/2010

Further seed collection from Ocoee River population.