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sand dune chinchweed

Rusby's chinchweed, Rusby's cinchweed

Habit Annuals or perennials, 2–50 cm (across or high); herbage spicy-scented. Annuals, 5–50 cm (taprooted); herbage spicy-scented.
Stems

prostrate to erect, usually sparsely to densely puberulent (sometimes in decurrent lines), sometimes glabrate.

erect or ascending, glabrous or sparsely puberulent (in decurrent lines).

Leaves

narrowly linear, 10–35 × 0.2–1.8 mm, margins with 1–5 pairs of setae 1–2 mm, faces glabrous (abaxial submarginally dotted with broadly elliptic to circular oil-glands 0.2–0.3 mm, sometimes with additional, scattered oil-glands).

linear to narrowly elliptic, 10–50 × 1–5 mm, margins with 1–3 pairs of setae, faces glabrous or sparsely puberulent (dotted on margins with round oil-glands 0.2–0.7 mm).

Peduncles

filiform, (3–)7–35(–54) mm.

20–80 mm.

Involucres

cylindric.

campanulate.

Ray florets

5;

corollas 3.5–5 mm.

8(–13);

corollas 5–11 mm.

Disc florets

3–7;

corollas 2–3 mm (2-lipped).

(7–)20–55;

corollas 3.5–5 mm (2-lipped).

Phyllaries

distinct, linear-oblanceolate, 4–5 × 0.8–1 mm (dotted with 1–2 elliptic, subapical oil-glands 0.2–0.3 mm, sometimes with additional, smaller submarginal or scattered oil-glands).

distinct, oblong or narrowly obovate, 4–7 × 1–2 mm (dotted with 0–2, subterminal oil-glands plus 2–4 pairs of inconspicuous, round to narrowly elliptic, submarginal oil-glands).

Heads

borne singly or in diffuse, cymiform arrays.

borne singly or in open, cymiform arrays.

Cypselae

2.5–3 mm, strigillose;

pappi of 0–5, antrorsely scabrid bristles or slender scales 1–2 mm plus 0–5 entire or irregularly lacerate scales 0.2–0.7 mm.

3–4.5 mm, strigillose or short-pilose;

ray pappi of 1–4, antrorsely barbed awns 1–4 mm or coroniform;

disc pappi of 15–30, antrorsely barbed bristles 2.5–5 mm or coroniform.

2n

= 48.

= 24 (as P. palmeri).

Pectis glaucescens

Pectis rusbyi

Phenology Flowering year round. Flowering Jul–Oct.
Habitat Sandy or gravelly soils, grassy areas, openings in pinelands, scrub, roadsides Deserts, desert grasslands, arid scrub, dry woodlands
Elevation 0–50 m (0–200 ft) 600–1600 m (2000–5200 ft)
Distribution
from FNA
FL; West Indies (Bahamas, Hispaniola, Jamaica)
[BONAP county map]
from FNA
AZ; Mexico (Baja California Sur, Sinaloa, Sonora)
[WildflowerSearch map]
[BONAP county map]
Discussion

Pectis glaucescens is widespread in southern Florida and the Bahamas. Human disturbances, especially road constructions, have created habitats suitable for it. It grows most commonly on limestone soils in open, grassy sites. Occasionally, it is a lawn weed.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Pectis rusbyi is much less common in Arizona than P. papposa var. papposa, with which it sometimes grows.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 21, p. 225. FNA vol. 21, p. 227.
Parent taxa Asteraceae > tribe Heliantheae > subtribe Pectidinae > Pectis Asteraceae > tribe Heliantheae > subtribe Pectidinae > Pectis
Sibling taxa
P. angustifolia, P. cylindrica, P. filipes, P. humifusa, P. imberbis, P. linearifolia, P. linifolia, P. longipes, P. papposa, P. prostrata, P. rusbyi, P. ×floridana
P. angustifolia, P. cylindrica, P. filipes, P. glaucescens, P. humifusa, P. imberbis, P. linearifolia, P. linifolia, P. longipes, P. papposa, P. prostrata, P. ×floridana
Synonyms Chthonia glaucescens, P. leptocephala, P. lessingii P. palmeri
Name authority (Cassini) D. J. Keil: Sida 11: 386. (1986) Greene ex A. Gray: in A. Gray et al., Syn. Fl. N. Amer. 1(2): 361. (1884)
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