Novon 19: 131. 2009.
Herbs, annual, caulescent; with slender taproot. Stems densely leafy distally, nearly leafless proximally, with many slender, ascending branches from base. Leaves cauline, alternate, often appearing subverticillate and densely tufted; stipules absent; sessile; blade margins entire. Inflorescences spikes, densely leafy. Flowers bisexual, actinomorphic, buds nodding, becoming erect; floral tube deciduous (with sepals, petals, and stamens) after anthesis, relatively narrow, with basal nectary; sepals 4, reflexed singly or in pairs; petals 4, yellow, fading pale yellowish orange, without spots; stamens 8 in 2 unequal series, epipetalous ones sometimes very reduced, or 4 in 1 series, epipetalous ones absent, anthers versatile, pollen shed singly; ovary 4-locular, stigma entire, subglobose, surface probably wet and non-papillate. Fruit a capsule, straight, strongly flattened, somewhat torulose, regularly loculicidal, dehiscent nearly throughout length; sessile. Seeds numerous, in 1 row per locule, narrowly obovoid, smooth, shiny, without dots or blotches. x = 7.
w North America.
Species 2 (2 in the flora).
R. A. Levin et al. (2004) found strong molecular support for Neoholmgrenia in a clade with Camissoniopsis and Tetrapteron. P. H. Raven (1969) found Neoholmgrenia (as Camissonia sect. Nematocaulis) to be one of the most distinctive groups in Camissonia by virtue of its relatively short (less than 10 mm), flattened capsules and densely clustered leaves near the tips of otherwise leafless stems. Reproductive features include: self-compatible; flowers diurnal; outcrossing and pollinated by small bees or flies, or autogamous and occasionally cleistogamous (Raven).