This is the weed responsible for "killer lawns". This patch in particular is just outside George's house (where I step on it every day, dammit!). Salient features:
| GEN | low herb |
| ST | bristly |
| LF | dissected, bristly |
| INFL | sess tiny heads, all fls appear same sex |
| PHYL | many, all same, broad and convex with sharp ~1mm spine at tip, glab |
| RECEPT | hairy? |
| FL | indet color |
| PAP | none |