This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Monoecious glabrous herbs or shrubs, with simple or branched stems, alternate or rarely opposite, entire or toothed leaves, often with 2 glands at the base, the flowers bracteolate, in terminal spikes, apetalous, the bractlets 2-glandular. Staminate flowers several together in the axils of the bractlets, the calyx slightly 2-3-lobed; stamens 2-3, exserted. Pistillate flowers solitary in the axils of the lower bractlets; calyx 3-lobed, ovary 2-celled or 3-celled with a solitary ovule in each cavity; styles stout, somewhat united at the base. Capsule 2-lobed or 3-lobed, separating into 2 or 3 two-valved carpels. Seeds ovoid or subglobose. Embryo straight in the fleshy endosperm. [In honor of Dr. B. Stellingfleet, an English botanist]
About 15 species, mostly of tropical America and the islands of the Pacific Ocean, the following typical.
Stillingia sylvatica L. Mant. 1: 126. 1767.
A bright green slightly fleshy perennial herb. Stem rather stout, erect or assurgent, usually branched from the base, 1°-3 1/2° tall. Leaves obovate, oblong or elliptic, 5"-4' long, obtuse, or subacute, serrate with appressed teeth, often narrowed at the 2-glandular base, sessile; flowers in terminal spikes, lemon-colored, subtended by small bracts furnished with saucer-shaped glands; calyx cup-shaped; petals and glandular disk none; capsule depressed, 5"-7" in diameter, 3-lobed; seeds ovoid, 3" long, light gray, minutely pitted and papillose, the base flattened.
Stillingia salicifolia (Torr.) Small, with relatively narrower and serrulate leaves, ranges from Kansas to Texas.