Atriplex

Fruits are essential for identification, as well as lower leaves. Depauperate specimens without well-developed leaves may also not be identifiable. Atriplex patula and A. prostrata are halophytes, and have become abundant in response to winter application of salt to roads, sidewalks, parking lots, and other areas. In addition, A. heterosperma has been found along highways in southern Ontario and likely will occur in Michigan. It is like A. patula and A. prostrata but has rounded rather than ± triangular bracteoles, and is a taller, erect plant.

1. Bracteoles at maturity firm and hardened, their margins fused ca. one-third their length; leaves with conspicuous fine network of dark green veinlets (seen when scraped lightly with a sharp blade).

A. rosea

1. Bracteoles thin at maturity, their margins fused less than a third of their length, if at all; leaves with normal, inconspicuous venation.

2. Bracteoles obtuse to rounded at apex, neither toothed nor tuberculate, the fruit appearing central; pistillate flowers of 2 kinds, most with bracteoles, vertical fruits, and no perianth, the others without bracteoles, the fruit horizontal, and with perianth.

A. hortensis

2. Bracteoles acute, usually toothed and/or tuberculate, the fruit nearly basal; pistillate flowers all alike, with bracteoles, vertical seeds (but these dimorphic: larger and pebbled brown or smaller and glossy black), and without perianth.

3. Lower leaves lanceolate to narrowly ovate, cuneate to the base, basal lobes, if present, forward directed.

A. patula

3. Lower leaves ± broadly triangular, truncate at the base; basal lobes spreading to reflexed.

A. prostrata

All species found in Atriplex

Atriplex hortensisGARDEN ORACHE 
Atriplex patulaSPEARSCALE 
Atriplex prostrataTRIANGLE ORACHE 
Atriplex roseaSALTBUSH 

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. August 19, 2017. http://michiganflora.net/genus.aspx?id=Atriplex.