January 2019 – Native Plant of the Month
Written by Guest Contributor: Elenore Goode
Elymus/Wildrye genus – Prairie/Canada Wildrye and Virginia Wildrye – Elymus canadensis and Elymus virginicus, etc.
Elymus is an agriculturally and ecologically important genus of mid-size cool season perennial bunchgrasses, and many different species are found in a variety of habitats throughout Texas. Cool season grasses grow starting in fall and winter, when the warm season grasses are beginning to go dormant. Elymus canadensis (featured in the pictures) and Elymus virginicus are two of the most common species that are fairly widespread across the state. While these two species are generally distinguished by their drooping (canadensis) vs upright (virginicus) seed culms, Elymus species may also have multiple varieties that occur within them (as with canadensis), have been found to hybridize, or have been said to be simply different forms within the same species (Guide to Texas Grasses – Robert B. Shaw).
In Central Texas, the versatile Wildryes are frequently found growing in shade or sun along lowland and upland riparian areas, woodland edges, meadows, prairies, forests, etc., with quite a bit of variability between all the species as to preferred moisture and sun conditions. Though they love to grow in the moist and deep soils and creek banks, they aren’t actually too picky when planted elsewhere. Even within one species, such as Prairie Wildrye/Elymus canadensis, some stands are happy in full sun when they have enough soil and moisture, and many others love to grow in the shaded understory of large trees, especially if they are in shallower soils or further from water.
Elymus species are very hardy grasses that are still common and somewhat abundant in the wild compared to many other native cool season forage plants. Their habit is to go dormant in dry summers unless they are in a moist area, but these grasses will otherwise have green growth for much of the year. Cool and moist conditions at the end of spring will prolong their growth into summer before going dormant.
They are important forage grasses that reliably provide food for wildlife, livestock, and soil microorganisms during winter when green forage is otherwise scarce. These grasses are generally grazed in rotational systems from fall through spring, but then avoided after their long seed culms go to seed at the start of summer, as these seed culms are said to be potentially problematic to livestock due to possible fungal growth. But while the livestock avoid it, the thatch and seeds they produce will be used by wildlife for nesting material and food.
Wildryes are also an excellent grass to use for pasture re-vegetation and habitat restoration projects, since their seeds are easy to find, collect, and germinate, even in poor soils. Their seeds establish exceptionally well and quickly compared to many other native grasses, and love shade or sun. Elymus stands can be very prolific in combination with deciduous forests that protect them in summer and then let the sunlight through in winter. Wildrye species are all-around great for improving degraded habitat conditions by revitalizing disturbed soils and bridging the temporal fragmentation of food sources that is exacerbated by low species diversity.