Merremia

Dennstedt ex Endlicher

Gen. Pl. 18: 1403. 1841. name conserved

Etymology: Presumably for Blasius Merrem, 1763–1824, German professor
Treatment appears in FNA Volume 14.

Perennials [shrubs]. Stems twining-climbing [erect or prostrate], glabrous or hairy. Leaves petiolate; blade usually palmately lobed or palmately compound, sometimes not lobed or compound, 15–70(–150) mm, surfaces glabrous or hairy. Inflorescences 2–12(–20+)-flowered cymes or umbelliform clusters or flowers solitary. Flowers: sepals oblong, ovate, ovate-lanceolate, or rhombic, 3–30 mm, glabrous or hairy; corolla usually cream, white, white with purplish throat, or yellow, rarely rose, campanulate to funnelform, 15–60 mm, limb subentire or 5-toothed, -angled or -lobed; anthers twisted after dehiscence; pollen usually 3–9-colpate, rarely aggrecolpate, not echinate; styles 1; stigmas globose or 2-lobed, lobes globose. Fruits capsular, usually ± globose, sometimes quadrangular, dehiscence irregular or valvate. Seeds 1–4(–6), ± trigonous, glabrous or hairy. x = 15.

Distribution

s United States, Old World subtropics and tropics, introduced in Mexico, West Indies, Central America, South America.

Discussion

Species 80+ (6 in the flora).

Merremia hastata Hallier f. [≡ M. tridentata (Linnaeus) Hallier f. subsp. hastata Ooststroom, Xenostegia tridentata (Linnaeus) D. F. Austin & Staples subsp. hastata (Ooststroom) Parmar] was recorded from ballast in Georgia in 1902; it evidently did not persist in the flora area.

A. R. Samões and G. W. Staples (2017) treated Merremia aegyptia as Distimake aegyptius (Linnaeus) A. R. Samões & Staples, M. cissoides as D. cissoides (Lamarck) A. R. Samões & Staples, M. dissecta as D. dissectus (Jacquin) A. R. Samões & Staples, M. quinquefolia as D. quinquefolius (Linnaeus) A. R. Samões & Staples, M. tuberosa as D. tuberosus (Linnaeus) A. R. Samões & Staples, and M. umbellata as Camonea umbellata (Linnaeus) A. R. Samões & Staples.

Selected References

None.

Key

1 Leaf blades not lobed or compound; inflorescences usually 3–20+-flowered umbellform clusters, flowers rarely solitary. Merremia umbellata
1 Leaf blades palmately lobed or compound; inflorescences 2–9-flowered cymes or flowers solitary. > 2
2 Leaf blades palmately lobed. > 3
3 Leaf lobe margins crenate, dentate, or irregularly pinnati-sinuate; corollas white with purplish throats. Merremia dissecta
3 Leaf lobe margins entire; corollas yellow. Merremia tuberosa
2 Leaf blades palmately compound. > 4
4 Leaflet margins dentate or entire; sepal abaxial surfaces hirsute, glabrescent. Merremia aegyptia
4 Leaflet margins usually dentate, sometimes remotely serrate to subentire, rarely entire; sepal abaxial surfaces glabrous or hairy, hairs glandular and setaceous. > 5
5 Sepals: outer and inner 10–18 mm, apex acuminate, abaxial surface hairy, hairs glandular and setaceous. Merremia cissoides
5 Sepals: outer 3–5 mm, inner 4–7 mm, apex obtuse, abaxial surface glabrous. Merremia quinquefolia
... more about "Merremia"
Daniel F. Austin† +
Dennstedt ex Endlicher +
s United States +, Old World subtropics and tropics +, introduced in Mexico +, West Indies +, Central America +  and South America. +
Presumably for Blasius Merrem, 1763–1824, German professor +
Merremia +
Convolvulaceae +