Melica in Oregon and Washington
There are nine native species of Melica in Oregon and Washington and one ornamental that has escaped from cultivation. Common names for Melica species are oniongrass and melic. The name oniongrass comes from the fleshy corms found in many members of this genus. Collectors who "top snatch" grasses often miss this key feature because the culm easily detaches, leaving the corms below ground.
Like Bromus, Melica has closed sheaths. The sheath may be closed to the top or have a V-neck opening.
The spikelets of Melica have bisexual florets at the base and sterile florets at the tip. The sterile florets are smaller, consisting of an empty lemma and no palea. Because these are considered rudimentary florets, they are often called rudiments. These sterile florets come in two shapes: a smaller version of the fertile florets or truncate, rounded club-shaped nubbins.
Another characteristic to note is the hyaline margin of the glumes, which appears transparent in fresh plants and papery white in dried specimens. Also, the glumes and lemmas often appear reddish purple.
The Melica species that lack corms are called melics and the ones with corms are called oniongrasses. We'll look at the four melics first, followed by the five oniongrasses.
Two of our Melica species have obvious awns on their lemmas, while one has an inconspicuous awn that is not always present. The two clearly awned species are Melica aristata (awned melic) and Melica smithii. Melica harfordii has tiny awns that are often absent. These three melics lack corms, as does one other native species, Melica stricta.
Awned melic grows in the forests of the Cascade Mountains from southern Washington to southern Oregon, where it extends into the Klamath (Siskiyou) Mountains. This species does not have corms or bulbous bases, so it might be confused with a fescue, but the closed sheaths and longer membranous ligule reveal that it is not a fescue. A key feature is the terminal floret in each spikelet reduced to an empty lemma lacking a palea.
Smith's melic is our rarest melica. Many of the reports of it are misidentified Bromus vulgaris (or some other brome) or Festuca subulata. It probably was not so rare before domestic livestock were introduced to the Oregon Territory. It is found in shady riparian areas, a habitat that has been extensively damaged by livestock grazing. The melic is particularly vulnerable to trampling; it was probably never a major source of forage.
The thin panicle branches of Melica smithii angle outward or downward from the central axis of the inflorescence. The mechanics of this spreading or reflexed angle are accomplished by pulvini (singular pulvinus), which look like little bulges in the branch angle. The branches do not droop; they are pushed downward by the pulvini.
Another feature that distinguishes this species from awned melic is the distance between florets within the spikelet: the rachillas are longer. Each lemma has a bifid tip with an awn extending from the central vein between them.
I learned this grass years ago and did not know it had awns until the field guide was at the proof-reading stage. I assure you that these awns are inconspicuous to the point of being missing-in-action. Since it lacks corms, you might not recognize it as a melic the first time you see it. But look for closed sheaths and reddish culm bases in the dense clumps this grass forms. It grows in and west of the Cascade Range in both states, and is particularly common in the Siskiyou Mountains.
red culm bases
Unlike the previous two melics, which grow on moist sites, Harford's melic grows in sunny, dry grasslands or rocky slopes.
Rock melic lacks both awns and corms, but you will recognize it immediately by its narrow, raceme-like panicle. The V-shaped spiklets dangle from sharply-bent pedicels. It is rare in our area, growing only in southeastern Oregon (into northern California) on dry, rocky slopes, from montane to alpine.
Now for the five oniongrasses:
Little oniongrass is the smallest of our Melica species. It grows on the east slope of the Cascades in Washington. In Oregon it is found east of the Cascades in the Blue Mountains and other ranges in the southern part of the state, extending into southwestern Oregon across the Cascade-Siskiyou Monument. It is often found in open sites on soils with a higher clay content, and sometimes occurs on soils from serpentine parent material.
The lower panicle branches often stick out at right angles during flowering.
The culms grow from clusters of fleshy corms.
The most distinctive feature of this species is the swollen rachilla, which appears fleshy in fresh plants and wrinkled and dull orange-brown in dried specimens. The rachilla is the connection between florets in the spikelet, so look for it at the base of the lemma.
A key feature for this species is the long, slenderly acuminate spikelets. There are often long, sparse hairs on the lemmas, especially in the veins and along the margins near the base. Note the translucent glumes.
Alaska oniongrass is the most common and widespread of our Melica species, occuring on both sides of the Cascades in both Oregon and Washington. It is a common understory grass in mesic forests in the mountains.
Alaska oniongrass has open panicles with upper branches ascending and lower branches spreading to drooping. The leaves have a characteristic sheen. Once you have an eye for that, you no longer need to look for the bulbs.
Geyer's oniongrass is another Melica species with open panicles. It grows west of the Cascade Range, but is nearly extirpated from the Willamette Valley part of its range. The best place to look for it is in southwestern Oregon, in dry grasslands, oak savannas, and open woodlands, especially on ultramafic (serpentine) sites.
When it comes to common names, this oniongrass is THE oniongrass, known simply as oniongrass. It grows in the Cascades in Washington and as far south as the Mt. Hood region in Oregon. It can be found in the other mountain ranges in eastern Oregon as well as in the Cascade-Siskiyou region in southwestern Oregon. Its distribution bears some similarity to that of Melica fugax. Its habitats include dry, rocky grasslands and sagebrush steppe and relatively mesic sites. For example, I've seen it in aspen stands in the drainages on Steens Mountain.
Oniongrass has narrow panicles, with the culms clustered close together. This bunch form is caused by the bulb-like bases being nearly sessile on the rhizomes.
Purple oniongrass has lovely purple-tinged spikelets and a narrow panicle like Melica bulbosa, but the culms are not clumped because the corms are attached to the rhizome by a root-like structure that is 10-30 cm long. When you excavate the bulb-like base, look for a "tail" attached to the base of it. Without digging out the rhizomes, you can infer which species it is by the spacing between the culms. In a dry meadow habitat, it is easy to overlook purple oniongrass because it grows as individual stems.