Horrid Herrickia

Herrickia horrida is known only from the Animas River basin, in Colfax County, northern New Mexico, and Las Animas County, southern Colorado.

Subshrubs or perennials, 30–60 cm cespitose; rhizomes woody, elongate, branched. Stems 1–20+, erect, branched, straight to ± flexuous, long- and short-stipitate-glandular, more densely so distally. Leaves cauline, proximal reduced and deciduous by flowering, coriaceous, rigid; sessile; blades oblong to oblong-ovate or ovate to nearly orbiculate, 10–45 × 4–30 mm, gradually reduced distally, bases cordate-clasping, main veins marked, margins sharply spinulose-serrate, scabridulous, short-stipitate-glandular, apices acute to obtuse, mucronate, faces scabrellous, ± short-stipitate-glandular. Heads 1–30+ in open corymbiform arrays or borne singly at ends of long, leafy branches. Peduncles 0.3–4 cm, densely stipitate-glandular; bracts 0–3, often proximal to heads and appearing to be part of involucres, foliaceous, margins entire or ± serrate. Involucres campanulate, 8.5–12 mm. Phyllaries (ca. 40) in 5–6 series, spreading, sometimes purplish tinged (inner or bases of outer), keeled, linear-lanceolate to oblanceolate, lance-oblong, or lanceolate, coriaceous, margins narrowly scarious, hyaline, sometimes purplish distally (inner), erose, short-stipitate-glandular along foliaceous distal parts, apices acute and spinulose to long-cuminate (innermost), often purplish-margined, faces short-stipitate-glandular; outer apically broadly foliaceous ¹ / 3 – ⁹ / 10 (foliaceous part often wider than base), inner usually narrowly foliaceous ¹ / 3 or less, sometimes green parts lanceolate apically along midnerves or none. Ray florets 17–20; laminae purple, 15–22 × 1.2–2 mm. Disc florets ca. 29; corollas yellow turning purplish, barely ampliate, ca. 8.2 mm, tubes shorter than funnelform throats (ca. 2.5 mm), lobes erect to spreading, triangular, 0.6–0.8 mm. Cypselae brown, fusiform, ± compressed [mature size not available], ribs 7–10, glabrous; pappi of (ca. 40) tawny bristles 7–7.5 mm. 2n = 18.

Aster horridus (Wooton & Standley) S. F. Blake; Eurybia horrida (Wooton & Standley) G. L. Nesom

Herrickia horrida is a species of flowering plant in the family Asteraceae known by the common name horrid herrickia. It is native to Colorado and New Mexico in the United States, where it occurs only in the Animas River basin. It is often included in genus Eurybia.

Herrickia horrida is a clumpy perennial herb or subshrub growing 30 to 60 centimeters tall from a woody rhizome. There are one to many stems which are coated in resin glands. The leaves are oval or oblong in shape with bases that clasp the stem. They are up to 4.5 centimeters in length. They are tough, glandular, coated in rough hairs, and lined with spiny teeth on the edges. The inflorescence may be a single flower head or an array of several heads. Each head is lined with glandular green or purplish phyllaries. It contains purple ray florets which may be up to 2.2 centimeters long, and yellow or purplish disc florets. Blooming occurs in summer, or as late as October. The fruit is an achene with a pappus of bristles.

Herrickia horrida grows on dry mountain slopes and canyons, often in oak woodlands, pinyon-juniper woodlands and grasslands. Most of its habitat is rugged and inaccessible, which helps protect it from human threats.