Flora of North America species comparison

arising directly from the root, erect to spreading, slender, solid, not fistulose or disarticulating into ringlike segments, sparsely to densely glandular.

persistent through anthesis or quickly deciduous, essentially basal, rosulate;

petiole indistinct;

blade linear to spatulate, margins entire.

terminal, cymose;

branches mostly dichotomous, not brittle or disarticulating into segments, round, glabrous or sparsely glandular;

bracts 3–5, distinct or connate basally, opposite and linear to narrowly triangular, positioned to side of node, 3-lobed and broadly triangular, or forming a perfoliate disk, leaflike to scalelike, awned, occasionally glandular, glabrous to pubescent.

present or absent, erect or deflexed, slender or stout.

1 per node, not ribbed, tubular, narrowly turbinate;

teeth (3–)4, erect to spreading, awn-tipped.

2–10 per involucre at any single time during full anthesis;

perianth white to rose or greenish yellow, broadly campanulate when open, narrowly urceolate when closed, glabrous or pubescent abaxially;

tepals 6, connate 1/4–1/3 their length, monomorphic or dimorphic, entire apically;

stamens 9;

filaments basally adnate, glabrous or minutely papillate basally;

anthers cream to pink or red, ellipsoid to oval.

usually included, light to dark brown or maroon, not winged, globose-lenticular, glabrous.

embryo curved.

= 20.