Grass Family (Poacae). Nodding needlegrass is a native, long-lived, cool season tufted perennial bunchgrass. It is very similar to Nassella pulchra (purple needlegrass), but is generally smaller, with finer leaf blades, and the terminal segment of the awn flexuous. It also produces more flower spikes. The basal leaf blades are numerous, narrow, and glaucus.
Stipa cernua, nodding stipa
Regularity: Regularly occurring
Global Range: This species is known from the United States and Mexico. It's distribution, however, is restricted. In the United States it is only known from California (Kartesz 1999) and in Mexico, it is only known from northern Baja California, Mexico (Gould and Moran 1989).
In California, this grass is especially adapted to sandy, well-drained, loamy soils, but will tolerate rocky soil. It is native to chaparral and dry slopes in lower elevations. It thrives in full sun, and also grows in partial shade. It will tolerate heat and wind.
Nodding needlegrass is found is the southwestern United States in lower elevations with a coastal influence. For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site.
Nodding needlegrass does well in disturbed sites and is valuable for erosion control, because of its strong root system. However, it does not tolerate disturbance after planting. It will go dormant after flowering without additional water (facultatively dormant), and does best with no summer water after the first year in the ground. Small amounts of routine watering may keep it green all year, but may also kill it. It is very drought tolerant, and intolerant of flooding. In dense stands, it can completely inhibit certain weeds, such as yellow starthistle. Abundant seed production is usually what helps maintain natural stands in non-grazed or lightly grazed areas. Plants need some protection from grazing during flowering to ensure seed formation and food storage in the crown. Once established, it is generally fire tolerant, but not fire resistant. The season of a burn is the most important factor in determining the severity of the effects on the plants. It will re-sprout after spring or fall burns, but summer burns can be damaging. Smaller plants are often less damaged by fire than larger plants because they burn less intensely and don’t smolder for long periods of time.
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: Unknown
Comments: It is unknown how many occurrences of this species there are. It is known from California and Mexico, but is highly degraded due to invasions of non-native species (Hamilton et al. 2002).
National NatureServe Conservation Status
Rounded National Status Rank: N2 - Imperiled
NatureServe Conservation Status
Rounded Global Status Rank: G3 - Vulnerable
Reasons: Nassella cernua is a grass known from only the United States and northern Baja California, Mexico. It is a member of native bunchgrass communities in California, that have been described as some of the most endangered ecosystem types in the United States. These native grasslands have been changed by non-native species, native to the Mediterranean area, since the mid-1700s. Nassella cernua, along with the grasslands, has declined because of the impacts of the non-native species. No direct information was found about the number of occurrences of this species that persist, but given the great decline of the grasslands it makes up, it is reasonable to assume that it too has declined significantly.
Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status (e.g. threatened or endangered species, state noxious status, and wetland indicator values).
Global Short Term Trend: Decline of 10-50%
Comments: Nassella cernua is a member of rare bunchgrass communities in California that have been degraded due to non-native species (Hamilton et al. 2002). It is expected that these communitites are still threatened, and that N. cernua is declining due to non-native plant invasion.
Global Long Term Trend: Decline of 50-90%
Comments: This grass species has undergone a long term decline. It is a main component of the California bunchgrass communities that are considered some of the rarest ecosystems in the United States. Nassella cernua along with Nassella pulchra are two native grass species that make up these bunchgrass communities. It is noted that since the time of the Spanish missions in the mid 1700s there have been enormous invasions of non-native grasses from the Mediterranean into California (Hamilton et al. 2002). The invasion of these non-native species has irrevocably changed the landscape to such a degree that the original extent of the bunchgrass communities is not known (Hamilton et al. 2002). Further, Hamilton et al. 2002 say that 80 to 100% of the cover of these communities is now comprised of non-native plant species.
Comments: While specific threats to this species were not found, it is part of rare Californian bunchgrass communtities that are threatened by non-native species, land clearing, farming, and extreme overgrazing (Hamilton et al. 2002). The following non-native species were identified by Hamilton et al. 2002 as greatly affecting the native bunchgrass communities, which presumably threaten N. cernua too: Bromus hordeaceous, Bromus diandrus, Avena fatua, and Avena barbata.
Cultivars, improved and selected materials (and area of origin)
‘LK415f’ Germplasm: Collected from San Luis Obispo County, California; Trusedale and Shells Roads. Township 27S and Range 15E Section 10. Elevation is approximately 1200 feet. Mean annual precipitation is 12-20 inches. Mean annual temperature is 60 degrees F.
Abundant seed matures in mid to late spring, with collection possible for 2 - 3 weeks. There are between 118,000 and 250,000 seeds/lb., and if planted at a rate of 1 lb./acre, there will be approximately 4.3 seeds/square feet. Sharp points on the seeds are augured into the soil by the twisting action of the awns. Also, seed can be harvested using a flow-vac or combine.
Nodding needlegrass will withstand mowing, especially after seed set and some traffic. It also requires some protection from grazing during the flowering period (late May-April).
Relevance to Humans and Ecosystems
Nodding needlegrass is used for restoration, critical area planting, cover crop, and wildlife habitat. It is probably one of the best grasses available for use in harsh conditions, such as subsoils, low fertility soils, hot ant dry meadows, roadcuts, and roadsides. It also provides good early forage for grazing animals.
Nassella cernua is a component of California and Baja California in native grasslands, chaparral, and juniper woodlands. This bunchgrass is found in the California Coast Ranges and Transverse Ranges (U.S.), and Peninsular Ranges (U.S. & Mexico).
This and many other native grasses of the California Floristic Province have declined because of the encroachment of introduced species of grasses, making native grasslands a very endangered habitat type, and this plant a listed Vulnerable species.
The perennial Nassella cernua bunchgrass has stems up to 2–3 feet (0.61–0.91 m) tall.  The narrow leaves have a waxy texture.
Nassella cernua is cultivated as a drought-tolerant ornamental grass by specialty plant nurseries, for use in native plant and wildlife gardens, drought tolerant landscaping, and for habitat restoration projects. 
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