Ageratina havanensis |
Ageratina rothrockii |
|
---|---|---|
Havana snakeroot, shrubby boneset, white mistflower, white shrub mistflower |
Rothrock's snakeroot |
|
Habit | Shrubs [trees], (30–)69–150(–200) cm. | Perennials, (20–)40–70(–150) cm (slender, fibrous-rooted crowns, with slender rhizomes). |
Stems | erect (brittle), puberulent to glabrous. |
ascending to erect, puberulent to glabrate. |
Leaves | persistent, opposite; petioles 3–10(–15) mm; blades deltate to broadly ovate or somewhat hastate, (2–)3–5(–8) × 2–5 cm, bases truncate to cuneate, margins dentate, apices acute, faces glabrous or nearly so, eglandular. |
opposite; petioles 2–20 mm; blades (3–5-nerved) lanceolate to lanceolate-ovate, mostly 3–6 × (1.5–)2–3 cm, bases obtuse to truncate, margins serrate to crenate, apices acute to acuminate, sparsely puberulent abaxially, mostly along nerves. |
Peduncles | 2–14 mm, minutely puberulent. |
5–12(–20) mm, puberulent. |
Involucres | 4–6 mm. |
5–7 mm. |
Corollas | white to slightly pinkish, glabrous. |
white, lobes short-villous. |
Phyllaries | apices acute, abaxial faces glabrous or nearly so. |
apices acute, abaxial faces glabrous or glabrescent, eglandular. |
Heads | clustered. |
clustered. |
Cypselae | hispid. |
sparsely and finely strigose-hirsute. |
Powell | on label]. |
|
2n | = 34. |
= 85 [ca. 100, fide A. M. |
Ageratina havanensis |
Ageratina rothrockii |
|
Phenology | Flowering mainly (Sep–)Oct–Nov(–Dec), also Apr–Jul. | Flowering (Jul–)Aug–Oct. |
Habitat | Bluffs, limestone outcrops and slopes, ledges along streams, often in oak-juniper woodlands | Rocky slopes and ledges, in oak-juniper, pine-oak, pine, aspen, and spruce-fir woodland |
Elevation | 100–900 m (300–3000 ft) | 1700–2400 m (5600–7900 ft) |
Distribution |
TX; Mexico; West Indies (Cuba)
|
AZ; NM; TX; Mexico (Chihuahua, Coahuila, Durango, Sonora)
|
Discussion | Ageratina havanensis apparently is the only species of the genus in the flora area with evergreen-persistent leaves. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Ageratina rothrockii is similar to A. altissima, probably its western vicariant, and the two perhaps would be justifiably treated as conspecific. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 21, p. 552. | FNA vol. 21, p. 550. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Eupatorium havanense | Eupatorium rothrockii |
Name authority | (Kunth) R. M. King & H. Robinson: Phytologia 19: 222. (1970) | (A. Gray) R. M. King & H. Robinson: Phytologia 19: 216. (1970) |
Web links |