Pectis humifusa

Swartz

Prodr., 114. 1788.

Common names: Yerba de San Juan
Introduced
Treatment appears in FNA Volume 21. Treatment on page 225. Mentioned on page 224.

Annuals or perennials, 2–25 cm (across; bases often ± woody); herbage not scented. Stems prostrate (mat-forming, densely leafy), puberulent (in decurrent lines). Leaves oblong-oblanceolate to obovate, 3–17 × 1.5–4 mm wide, margins with 2–6 pairs of setae 1–2 mm, faces glabrous (dotted with scattered, round oil-glands 0.1–0.2 mm). Heads borne singly or in congested, (leafy) cymiform arrays. Peduncles 1–12 mm. Involucres campanulate. Phyllaries distinct, obovate, 4.5–6 × 2–4 mm (faces densely dotted with scattered, circular oil-glands 0.05–0.2 mm). Ray-florets 5; corollas 3.5–5 mm. Disc-florets 12–21; corollas 2.5–3.5 mm (2-lipped). Cypselae 2.5–4 mm, mostly puberulent (ray cypselae abaxially glabrous); ray pappi of 2–3 slender, aristate scales 1.5–2.5 mm plus 2–10 lacerate scales or bristles; disc pappi of 4–15, antrorsely scabrid bristles or aristate scales 2–3 mm plus 0–15 bristles or scales. 2n = 72.


Phenology: Flowering year round.
Habitat: Sandy soils
Elevation: 0–10 m

Distribution

V21-542-distribution-map.gif

Fla., West Indies (Puerto Rico), West Indies (Lesser Antilles), South America (Suriname)

Discussion

Pectis humifusa has been reported once from Florida (D. J. Keil 1975c), where it is probably adventive. In the Lesser Antilles, it occurs most frequently in the salt spray zone near the seashore; on some islands, it occurs inland as well.

Selected References

None.

Lower Taxa

None.
... more about "Pectis humifusa"
not tailed +, rounded +  and obtuse +
darkened +  and pale +
connate +  and distinct +
subequal +
scarious +
usually ovate +  and lanceolate +
usually deltate +  and lanceolate +
indeterminate +  and determinate +
David J. Keil +
Swartz +
decurrent +
compound +  and simple +
obovate;oblong;obovate;oblong;oblanceolate;linear to elliptic +
winged;ribbed;winged;ribbed +
tuberculate +  and rugose +
barbellulate +  and barbellate +
Yerba de San Juan +
yellow +  and reddened +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
cylindric +  and narrowly clavate ribbed or angled +
fertile +  and bisexual +
Fla. +, West Indies (Puerto Rico) +, West Indies (Lesser Antilles) +  and South America (Suriname) +
0–10 m +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Sandy soils +
cymiform +, corymbiform +, discoid +  and radiate +
in congested , cymiform arrays +  and singly +
indeterminate +
homogamous +  and heterogamous +
not scented +
each +  and sessile +
0.2 cm2 mm <br />0.002 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
campanulate +
oblong-oblanceolate;obovate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
deltate +  and lanceovate +
dentate to pinnatifid or palmatifid +  and entire +
2-carpellate +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
persistent +
coroniform +
0.1 cm1 mm <br />0.001 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
Flowering year round. +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
3 +  and 15 +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
bearing subulate enations +, hairy +  and bristly +
pitted +  and smooth +
flat;hemispheric +
2 +  and 3 +
aristate +
slender +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
exalbuminous +
Introduced +
branched +  and simple to much +
prostrate +  and erect +
puberulent +
appendaged +  and truncate +
hirsutulous +  and glabrous +
papillate +
Undefined (tribe Undefined) subtribe Tageteae +
Pectis humifusa +
species +
cylindric +
toothed +  and entire +
perennial +  and annual +
2 cm20 mm <br />0.02 m <br /> (25 cm250 mm <br />0.25 m <br />) +
50 cm500 mm <br />0.5 m <br /> (120 cm1,200 mm <br />1.2 m <br />) +
shrub +  and subshrub +