Background

Ramps are a member of the onion family (Alliaceae) found in the eastern United States (Figure 1). They are a popular non-timber forest product (NTFP) that can be forest farmed for commercial sale.

There are two ramps found in the US: the relatively well-known wide leaf ramp (Allium tricoccum) and the lesser-known narrow leaf ramp (Allium burdickii). The wide leaf ramp is the more common of the two species. It is distributed widely across the eastern U.S. and grows in large patches that may occupy many acres. The narrow leaf ramp is relatively rare, restricted mostly to the Midwest, and grows in smaller, scattered patches. Additionally, the narrow leaf ramp has a shorter growing season, and does not grow as large as the wide leaf ramp. Narrow leaf ramps were only recently discovered in Pennsylvania, and little is known about the species abundance and habitat preferences in this state. While they are edible, it is best not to harvest narrow leaf ramps until more research can determine how widespread and numerous this species is in the state.

Range map of Allium tricoccum in the United States by county — Figure 1. Range of *Allium tricoccum* in the U.S. Photo: Eric Burkhart

Description

Size

Ramps are generally less than 12 inches in height (Figure 2).

Ramp plants with three leaves, left, and two leaves, right — Figure 2. Ramp plants with three leaves (left) and two leaves (right). Photo: Eric Burkhart

Flower

Ramps are slow-growing and require 5-7 years before they begin flowering. The flowers are small, white, and arranged in a cluster that is botanically referred to as an umbel. This flower cluster resembles a snowball and sits atop the leafless stalk (or scape) during June and July (Figure 3).

Fruit

After pollination, a ramp flower develops into a fruit that at first looks like it is forming three green berries. Part of the scientific name, tricoccum, in fact means "three-berries." This fruit eventually matures to form three capsules that split open at maturity to reveal three black seeds, one per capsule or "berry" (Figure 4).

Figure 4. Ramp seeds. Photo: Eric Burkhart

Leaves

Ramps also have a seasonal growth pattern in which leaves are produced during the spring months and then die-back or senesce before summer arrives. During this spring growth period, ramps can produce 1 to 4 broad green leaves, with more leaves added over the years (Figure 5). When crushed, the leaves have a notable smell often described as a combination of onion and garlic.

Stems

Stems and leaves grow from a storage structure called a bulb that sits near the soil surface. Bulbs have short roots attached to the bottom. There are two color "morphs" of ramps: stems may be greenish-white or reddish-purple (Figure 6). These can grow intermixed or only one color may be present per location. The cause of this difference in coloration is not known but these colors can be seen in garden onions and may be genetically determined.

Similar Looking Plants

Lily-of-the-valley (Convallaria majalis) and false hellebore (Veratrum viride) may be confused with ramps (Figure 7). These plants are deadly poisonous and can be found in the same habitat. Remember that ramps should always produce a notable onion and garlic smell when crushed or bruised.

Dispersal

Seeds are typically dispersed by gravity and fall nearby onto the ground beside the parent plant. Turkeys have been observed to browse on the seeds during the fall but probably don't disperse the seed.

Ramp bulbs split over time to form new plants in a process known as asexual reproduction (Figure 8). Resulting clones are initially connected underground by a structure called a basal plate but become separated into individual plants over time. Clonal growth and expansion are a primary reason why ramps can be found in clumps or patches.

Splitting ramp bulbs — Figure 8: Ramp bulbs splitting. Photo: Eric Burkhart

Site (Habitat)

Ramps can be found throughout Pennsylvania but are more common on the Allegheny plateau and Piedmont than in the Ridge and Valley province. Ramps are primarily found on east and north-facing slopes of deciduous forests by spring seeps, drainages, or areas that remain moist all year (Figure 9). Ramps are often associated with calcium-rich soils with a slightly acidic pH (around 5.5-7.0). They are commonly associated with limestone bedrock and with consistent soil moisture (wet areas such as floodplains and drainages).

The rich soils which ramps prefer are also preferred by many other species of plants. Certain plants can be used as indicators of a site which may be suitable for ramps (Table 1). On northern slopes, associated species include sugar maple (Acer saccharum) and blue cohosh (Caulophyllum thalictroides). In floodplains, ramps often are found growing with Jack-in-the-pulpit (Arisaema triphyllum), mayapple (Podophyllum peltatum), and bitternut hickory (Carya cordiformis).

Overstory Species

Table 1. Species commonly found growing with ramps.
Common Name	Scientific Name
Sugar maple	Acer saccharum
Basswood	Tilia americana
Bitternut hickory	Carya cordiformis
Tulip poplar	Liriodendron tulipifera
Black cherry	Prunus serotina

Understory Species

Common Name	Scientific Name
Blue cohosh	Caulophyllum thalictroides
Jack-in-the-pulpit	Arisaema triphyllum
Yellow trout lily	Erythronium americanum
Cut-leaf toothwort	Cardamine concatenata
Mayapple	Podophyllum peltatum

Figure 9. Ramps growing on a slope, showing the open canopy when ramp leaves are fully emerged. Photo Cathryn Pugh

Conclusion

Ramps are an edible non-timber forest product in the onion family. They have large smooth leaves, which can be seen from April to May and a cluster of white flowers that can be found in June-July (Table 2). Ramps are a slow-growing plant that can are usually found on eastern or northern slopes on moist sites with a limestone bedrock. They are often found on forestlands with two prominent "indicators" being sugar maple and blue cohosh.

Table 2. The stages of ramp development over the growing season in Pennsylvania.