Chamaesyce maculata is an annual C4 herb (Downton 1971), prostrate, mat forming, stems often pink, to 40 cm long, usually finely hairy, sap milky.
Leaves opposite, dark gray-green usually with reddish or dark spot, oblong 0.5-1.5 cm, widest below middle, no stalk.
Flowers tiny, inconspicuous, monoecious, but males and females grouped together, axillary (use lens), stamen one, pistil one, several males surrounding one female, clustered above a lobed bract; blooms and fruits June-Sept.
Fruit dry, a 3-lobed capsule, seeds 0.1 cm.
Wetland status: FACU-.
Frequency in NYC: Occasional. Probably more common than indicated by collections.
Habitat: Open, disturbed, soil, fill, curbs, street tree pits, sidewalk cracks, ball fields. Appears to tolerate compaction and drought.
Notes: Toxic due to photosensitization (Kingsbury 1964).