Shatterstone Phyllanthus urinaria

Chamberbitter is a summer annual, heavily branched at the base with ascending stems, often forming a mound 1 to 2 feet in height. Leaves are oblong in shape, 1/2 to 3/4 inch in length, on short branches, and look similar to compound leaves of some legumes. Although in the spurge family, chamberbitter stems do not exude a milky sap when broken. Flowers are small, inconspicuous, and greenish-white. Distinctive round fruit are borne on the undersides of the lateral branches at the leaf axils. Similar in appearance to long-stalked phyllanthus (Phyllanthus tenellus), the two species differ by the length of the seedpod stalks. Chamberbitter fruit are borne sessile (without stalks) whereas long-stalked phyllanthus stalks are about 1/4 to 1/2 inch long. Phyllanthus require substrate temperatures above 75 oF to germinate and thus are more common in the summer, but will persist into late fall in the southeastern US (and year-round in sub-tropical areas). Plants flower throughout the summer and fall then die after frost. Fruit forcefully expel seed short distances.

Insects, Diseases, and Other Plant Problems: Both species of Phyllanthus are particularly difficult to manage. Do not let plants go to seed. Inspect pots before planting and eradicate new infestations before they can spread. They are poorly managed by most preemergent herbicides labeled for use.