Nosema Prain

Erect herbs, branched or not. Stem and branches slender, pubescent. Leaves opposite, petioled. Verticillasters ∞-flowered, forming terminal, cylindric, racemose inflorescences, continuous or interrupted below. Flowers small. Bracts leafy below, gradually diminishing in size upwards. Calyx obliquely ovoid, 10-nerved, 2-lipped, the upper lip oblong, entire or very shallowly 3-lobed, the lower lip round, entire, much shorter than the upper lip; fruiting calyx tube flattened cylindric, transverse veins connecting the longitudinal nerves, inconspicuous, not deeply pitted. Corolla short; throat inflated, abruptly constricted towards the base; limb 2-lipped, the upper lip slightly shorter, unequally 3-lobed, the median lobe often very broad; lower lip oblong, entire, concave. Stamens 4, in two pairs, declinate; anther-cells confluent; filaments pubescent, those of the upper pair spurred with an appendage at the base. Nutlets ovoid, minute, smooth.