NYCTAGINACEAE, the Four-o'Clock Family
Herbs, with opposite entire leaves and flowers in small clusters surrounded by a broad open calyx-like involucre; the true calyx colored like a corolla; petals none (4-8 dm. high; flowers purple, in summer).
| 1a. Leaves lanceolate or narrower, sessile | Umbrella-wort, Oxybaphus hirsutus. |
| 1b. Leaves ovate, petioled | Umbrella-wort, Oxybaphus nyctagineus. |
ILLECEBRACEAE, the Knotwort Family
Herbs, with opposite entire leaves, and minute flowers without petals. (Prostrate spreading or freely branched plants, 3 dm. high or less; flowers in summer.)
| 1a. Stipules none; leaves slightly connate at base, subulate | Knawel, Scleranthus annuus. |
| 1b. Stipules present, but small; leaves elliptical or oval (Forked Chickweed) [— 2.] | |
| 2a. Stems pubescent; internodes seldom more than 1 cm. long | Forked Chickweed, Anychia polygonoides. |
| 2b. Stems smooth; internodes about 2 cm. long | Forked Chickweed, Anychia canadensis. |
AIZOACEAE, the Carpet-weed Family
Prostrate herbs, with whorled leaves and small whitish axillary flowers without petals, in summer.
| One species in Michigan | Carpet-weed, Mollugo verticillata. |