Subject: Setaria sp. (Foxtail Grass)

From: [email-masked] (Thomas Palmer)
Date: Tue, 20 Aug 1996 13:11:30 GMT

There's a common annual weed here (suburbs south of Boston) that resembles
Setaria viridis (Green Foxtail Grass) in most respects except that each
spikelet has 4-7 bristles below it instead of the 1-3 predicated in most
manuals, e.g. Gleason & Cronquist's 1991 MANUAL OF THE FLORA OF THE NE AND
ADJACENT CANADA.  Anyone else run into this?

Thomas Palmer ([email-masked])

---

From: scott white <[email-masked]>
Date: Wed, 21 Aug 1996 21:48:37 -0700

> Thomas Palmer ([email-masked])

There are other Setarias. In California, the Jepson Manual (Hickman, 
ed. 1993, Univ. of Calif. Press) has 3 species keying as "spiklet 
subtended by 4-15 bristles ..."; these include S. gracilis, S. pumila,
and S. sphacelata. S. gracilis is native and reportedly distributed to 
E N Amer. The others are European weeds. If your plant isn't in the 
regional manuals, then you probably have documented an addition to 
the region's flora. You should make a few specimens and give them to 
an herbarium. Also, try to find a copy of Flora Europa, and keying 
the plants there. It should be in a university library. 

The introduction and dispersal of weeds in new areas is a fascinating 
but poorly documented aspect of plant geography.

Best,
-SW