CPC Plant Profile: Green's Awnless Orcutt Grass
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Plant Profile

Green's Awnless Orcutt Grass (Tuctoria greenei)

Photograph of Tuctoria greenei Photo Credit: Copyright © 2008 Heather Davis
Description
  • Global Rank: N/A
  • Legal Status: N/A
  • Family: Poaceae
  • State: CA
  • Nature Serve ID: 144317
  • Date Inducted in National Collection:

Greenes tuctoria is an annual grass species found only in vernal pools. It grows in tufts of several stems, which are erect or decumbent and break easily at the base. The entire plant tends to be pilose, but is only slightly viscid. The stems are usually 5 to 15 centimeters (2.0 to 5.9 inches) tall and are not branched. Plants have purplish nodes and leaves no wider than 5 millimeters (0.20 inch). The inflorescence can be as much as 8 centimeters (3.1 inches) long; it may be partly hidden by the leaves when young, but is held above the leaves at maturity. (Recovery Plan).

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Updates
  • 10/01/2020
  • Seed Collection

Seeds have been collected at localities in Tehama and Glenn counties, and will continue to be collected in subsequent years at other localities. Seeds will be deposited at an appropriate seed storage facility. (Recovery Plan).

  • 10/01/2020
  • Reproductive Research

Dr. Heather Davis, Department of Biology of Sonoma State University, began an investigation in 2007 on the population genetics of Greenes tuctoria to determine how pollination ecology interacts with population genetics to control the plants reproductive success (Sonoma State University 2006).

  • 10/01/2020
  • Genetic Research

Dr. Heather Davis, Department of Biology of Sonoma State University, began an investigation in 2007 on the population genetics of Greenes tuctoria to determine how pollination ecology interacts with population genetics to control the plants reproductive success (Sonoma State University 2006).

Nature Serve Biotics
  • 05/02/2017

Restricted to vernal pools in the Central Valley of California. Of the total 43 occurrences ever recorded, 21 are currently considered historical and 2 are considered extirpated; 20 (47%) remain extant. Vernal pool habitats in California's Central Valley have been greatly reduced from pre-European times; the remaining habitats are limited in extent, fragmented, and are facing on-going degradation and elimination due to numerous housing development projects and other types of urban development, agricultural activities and development, grazing, the invasion of non-native plant species, and other threats.

Holly Forbes
  • 01/01/2010

Habitat destruction Competition with non-native species Inappropriate livestock grazing

Holly Forbes
  • 01/01/2010

22 occurrences are believed to be extant. The number of individuals varies dramatically from year to year. Fourteen localities of this species remain unprotected and all of these sites are on private lands. (5-year Review)

Holly Forbes
  • 01/01/2010

Dr. Heather Davis, Department of Biology of Sonoma State University, began an investigation in 2007 on the population genetics of Greenes tuctoria to determine how pollination ecology interacts with population genetics to control the plants reproductive success (Sonoma State University 2006). Seeds have been collected at localities in Tehama and Glenn counties, and will continue to be collected in subsequent years at other localities. Seeds will be deposited at an appropriate seed storage facility. (Recovery Plan).

Holly Forbes
  • 01/01/2010

Grazing is excluded from occurrences on conservation lands. Management on private lands is unknown. The majority of the localities of Greenes tuctoria do not have management plans, monitoring programs, or adequate funding to ensure that these localities are sustainable in perpetuity. (5-Year Review)

Holly Forbes
  • 01/01/2010

The Recovery Plan recommends research on genetics, taxonomy, biology, the effects of habitat management practices on this species and its habitat, and threats to vernal pool species and ecosystems.

Holly Forbes
  • 01/01/2010

Continued development of long term seed banks.

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Photos
Nomenclature
Taxon Tuctoria greenei
Authority (Vasey) J. Reeder
Family Poaceae
CPC Number 4353
ITIS 202500
USDA TUGR
Common Names Greene's Awnless Orcutt-grass | Greene's Orcutt Grass | Greene's tuctoria | awnless spiralgrass
Associated Scientific Names Tuctoria greenei | Orcuttia greenei
Distribution The majority of the 22 extant occurrences are in the Northeastern Sacramento Valley Vernal Pool Region, particularly in the Vina Plains. The next largest concentration is in the Southern Sierra Foothi
State Rank
State State Rank
California S1
Habitat

Greenes tuctoria has been found in three types of vernal pools: Northern Basalt Flow, Northern Claypan, and Northern Hardpan on both low and high terraces. (Recovery Plan).

Ecological Relationships

Optimum germination of seed occurs when the seed is exposed to light and anaerobic conditions after stratification (Keeley 1988). Germination occurs about two months following inundation (Keeley 1998). Plants do not tolerate inundation.At the Vina Plains Preserve, frequent associates of Greenes tuctoria are Eryngium castrense and Marsilea vestita. Elsewhere in the Sacramento Valley and in the San Joaquin Valley, Greenes tuctoria often grows in association with Eryngium vaseyi, Plagiobothrys stipitatus, and Alopecurus saccatus (foxtail). The rare Chamaesyce hooveri co-occurs with Greenes tuctoria at eight sites in the Sacramento Valley. Other rare plants that grow in the same vernal pools with Greenes tuctoria at a few occurrences are: Orcuttia pilosa, O. inaequalis, O. tenuis, Neostapfia colusana, and Gratiola heterosepala (Recovery Plan).

Pollinators
Common Name Name in Text Association Type Source InteractionID
Reintroduction
Lead Institution State Reintroduction Type Year of First Outplanting

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