Adenophyllum

Persoon

Syn. Pl. 2: 458. 1807

Etymology: Greek adeno, gland, and phyllon, leaf
Treatment appears in FNA Volume 21. Treatment on page 237. Mentioned on page 222.
Annuals, perennials, or subshrubs [shrubs], (20–)30–70[–250+] cm. Stems erect, branched from bases or throughout. Leaves cauline; mostly opposite (distal sometimes alternate); petiolate or sessile; blades (or lobes) ovate, oblanceolate, or linear, 1-pinnately lobed, ultimate margins ± toothed (teeth often bristle-tipped), faces glabrous or ± hirtellous to scabrellous (oil-glands usually borne at bases of lobes and subterminally near apices). Heads usually radiate, rarely discoid, borne singly. Calyculi of 3–5 or 12–22 linear to subulate bractlets (sometimes with 1–2 lobes, often bristle-tipped, usually bearing oil-glands). Involucres campanulate to obconic [hemispheric], [5–]7–20+ mm diam. Phyllaries persistent, 8–20+ in ± 2 series (weakly connate 1/3–3/4 their lengths, separating in age, mostly lanceolate to linear, margins of outer distinct to bases or nearly so, oil-glands in faces and near margins). Receptacles convex, ± pitted (socket margins fimbrillate to setose), epaleate. Ray florets usually 7–16[–16], rarely 0, pistillate, fertile; corollas yellow to orange or red-orange. Disc florets 25–70[100+], bisexual, fertile; corollas yellow to yellow-orange, tubes shorter than cylindric throats, lobes 5, lance-ovate to lance-linear. Cypselae obpyramidal [obconic], glabrous or ± strigose or sericeous; pappi persistent, of 8–20 scales in 1–2 series (single scales muticous, or unequally 3-aristate, or comprising 5–11 basally connate bristles). x = 7, 13.

Distribution

sw United States, Mexico, Central America.

Discussion

Species 10 (3 in the flora).

References

None.

Key

1 Annuals; calyculus bractlets eglandular; pappi: outer scales erose, inner each unequally 3-aristate Adenophyllum wrightii
1 Perennials or subshrubs; calyculus bractlets bearing oil-glands; pappi: each scale comprising 5–11 basally connate bristles > 2
2 Leaves 3–5-lobed (lobes linear to cuneate or oblanceolate, ultimate margins entire or toothed); disc florets 25–40; pappi of 8–12 scales Adenophyllum porophylloides
2 Leaves not lobed (blades ovate to oblanceolate, margins toothed); disc florets 50–80; pappi of 15–20 scales Adenophyllum cooperi