Corresponding author: Christian Feuillet (
Academic editor: S. Knapp
Feuillet C (2016) Two new combinations in
The genus
I studied the literature and type specimens. In the citation of types, “photo” refers to a print deposited in herbaria and “scan” refers to a picture posted online, available directly through herbarium sites, or sites like JSTOR or Europeana.
For the purpose of this paper, the Guiana Shield area is defined as the Venezuelan Guayana, the Guianas (Guyana, Surinam and French Guiana), and the part of Brazil north of the Amazon River and east of the Rio Negro.
Herbs or subshrubs. Leaves alternate, simple, entire. Trichomes on a pedestal of distinctly enlarged foliar epidermis cells. Inflorescences of single, scorpioid cymes, or flowers solitary. Flowers perfect; calyx 5–toothed or 5–lobed, persistent; corolla white, small, 5–merous, lobe’s margin involute; stamens 5, included; nectar disc at the base of the ovary; ovary functionally 4–locular, locules 1-seeded, style terminal, undivided, or absent, the stigma cryptically or clearly apically 2- or 4-fid. Fruit a schizocarp, lobed or unlobed, dry, 2–4 bony 1-seeded nutlets, embryos curved.
North America to Argentina, Africa, Arabian Peninsula to Indochina, Australia.
Based on
When they resurrected
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When
Because the name
The last treatment of
1 | Flowers solitary; pedicels 1–3 mm long; corolla white and yellow |
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– | Inflorescences 1–18 cm long; flowers sessile or sub-sessile, or pedicels obvious; corolla white or yellow |
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2 | Stem glabrous or puberulent; leaf blades glabrous or puberulent; corolla white, yellow at throat, lobes elliptic |
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– | Stem villose; leaf blades with long, stiff trichomes; corolla tube yellow, lobes white, ovate |
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3 | Petiole 4–15 mm long; raceme mostly geminate or ternate, ebracteate; stigma sessile, base as wide as the apex of the ovary, forming together a blunt cone |
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– | Petiole 0.3–2 mm long; raceme single or paired, bracteate; stigma morphologically clearly separate from the ovary, looking together like a mushroom or like a head with a hat or with a clear style |
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4 | Leaf blade Inflorescences always single; bract filiform to narrowly elliptic; calyx length greater than or less than half the corolla tube; corolla white; style 0.3–0.5 mm long |
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– | Inflorescences usually single and paired on the same plant; bracts ovate; calyx nearly as long as the corolla tube; corolla yellow; style 0.5–1 mm long |
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5 | Stem relatively coarse and stiff; leaves drying rather light colored; inflorescences up to 20 cm long, with 1–2 cm long peduncle; calyx shorter than half the corolla tube; corolla 4–6 mm long, salverform; anthers apically joined; stigma on a short style |
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– | Stem wiry, very slender; leaves usually drying dark colored; inflorescences epedunculate, up to 10 cm long; calyx longer than the corolla tube; corolla 2–2.5 mm long, tube urceolate; anthers not joined at apex; stigma sessile |
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Annual herb or subshrub, up to 0.25 m tall. Stems slender, erect or decumbent, up to 0.4 m long, sparingly strigose. Leaves: petiole 0.1–0.2 cm long, slender; lamina linear or elliptic or lanceolate or oblanceolate, 1–2.5 × 0.15–0.35 cm, apex acute, base acute, margin entire, both surfaces sericeous to strigose. Inflorescences epedunculate, slender scorpioid cymes, up to 15 cm long, bearing scattered bracts, filiform or subulate, 0.1–0.2 cm long, glabrescent. Flower sub–sessile: calyx longer than the corolla tube, lobes, 1.5–2 mm long at anthesis, glabrescent; corolla white, tubular, outside strigose, inside glabrescent, tube narrowed in the middle, lobes ovate with broadly open sinuses, about 1 mm long; stamens sessile, anther with an apical appendage, weakly coherent; ovary subglobose or globose, strigose; style lacking or nearly so; stigma sessile or sub–sessile, fertile base much wider than the apex of the ovary. Fruit on 0.5–1 mm long pedicel, depressed–globose; nutlets almost 1.5 mm long.
Venezuela (Amazonas, Bolívar), Guyana, Surinam, French Guiana, Brazil (Amapá, Amazonas, Pará, Roraima); also in Belize, Mexico, southeastern USA and from Trinidad to eastern Bolivia and Paraguay.
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Suffrutescent herbs up to 30 cm tall; stems stiff, erect or decumbent, 10–50 cm long, with abundant, loosely appressed trichomes. Leaves: petiole subnul–2 mm long, thin; lamina lanceolate to linear, revolute, 0.5–3 × 0.1–0.8 cm, apex acute, base acute, margin +/- revolute, adaxially sericeous, abaxially tomentose, trichomes base very large and looking calcified. Inflorescences terminal or axillary, up to 20 cm long, stiff scorpioid cymes, single, peduncle 1–2 cm long, with scattered linear or narrowly elliptic bracts, 2–3 mm long, sericeous. Flower subsessile: pedicel 0.5–1 mm long, calyx 2–3 mm long, deeply lobed, lobes unequal, shorter than 1/2 the length of the corolla tube, becoming twice as large at maturity, sericeous in and out; corolla white, strigose outside, tube narrow, 2–2.7 mm long, throat yellow, lobes spreading, 1.3–2 mm long, ovate, sinuses rounded and plicate; stamens subsessile, anthers ovate with short, obtuse, hairy, apical long appendages which are apically joined; ovary globose, 0.3–0.4 mm diam., glabrous; style short but obvious, about 0.5 mm long; stigma about as large as the ovary, split at apex. Fruit depressed globose, 4–lobed, 1.5–1.8 mm diam., strigose or hirsute; nutlets 1–1.5 mm long.
Venezuela (Bolívar) and Guyana; also Central America, Mexico, and the West Indies Southward to southern Brazil.
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Prostrate herbs. Stems villose, trichomes hyaline, somewhat ferruginous around the nodes. Leaves: petiole short; lamina lanceolate, 0.5–0.8 × 0.15–0.2 cm, apex acute, base attenuate, margin entire, both surfaces villose. Inflorescence: solitary, supra-axillary flowers, on 1–1.5 mm long pedicel. Flowers: calyx as long as the corolla tube, lobes, 2.2–2.7 mm long at anthesis, puberulent on both sides; corolla tube yellow with white lobes, outside strigose, inside pubescent, tube more or less cylindric, lobes ovate with narrow sinuses, about 1 mm long; stamens sessile, anther with a small appendage; ovary ca. 0.3 mm diam., globose, glabrous; style lacking; stigma sessile, widely conical. Fruit on 1.2–2 mm long pedicel, subglobose, 1.5 mm diam., glabrous, rostrate; nutlets about 1.2 mm long.
Guyana; previously only known from a few localities outside the Guiana Shield, Brazil (Ceará, Goiás, Minas Gerais), Venezuela (Apure). In our area it is known only by GUYANA, Upper Takutu–Upper Essequibo, W of the Kanuku Mtns, savanna near Mountain Point, 27 Feb–5 Mar 1985, fl,
Based on
Annual herbs, up to 15 cm tall, stems decumbent or prostrate, up to 30 cm long, glabrous or with scattered slender appressed trichomes. Leaves: petiole about 1 mm long, glabrous; lamina oblanceolate, 0.5–1.5 × 0.1–0.3 cm, apex acute to acuminate, base attenuate, margin entire, ciliate, adaxially glabrous, abaxially glabrous to puberulent. Flowers single, extra–axillary on leafy stems: pedicel up to 3 mm long, calyx of 5 lanceolate or cuneate, unequal lobes, 1.5–2.5 mm long at anthesis, puberulent in and out; corolla white, yellow at throat, tube swollen at base, 3–4 mm long, puberulent in and out, lobes ovate, 1–1.5 mm long, with sinus rounded, occasionally plaited with a minute lobule; stamens sessile, inserted about 0.5 mm from base, anthers joined, oblong, with an hairy apical appendage nearly as large as the anther; ovary obpyriform, about 0.5 mm diam.; style lacking or confused with the apex of the ovary; stigma sessile or subsessile, much larger at base; fruit rostrate, glabrous or nearly so, about 2 mm diam., obpyriform; nutlets ca. 1.5–2 mm long.
Venezuela (Bolívar), Surinam, French Guiana, and Brazil (Amazonas); also Greater Antilles and from Mexico to Brazil and eastern Bolivia.
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Herb or subshrub. Stems prostrate or decumbent, sericeous. Leaves alternate or subopposite: petiole 0.03–0.1 cm long, sericeous; lamina narrow lanceolate or oblanceolate, 0.6–1.3 × 0.1–0.2 cm, apex acute, base cuneate, margin entire, both surfaces sericeous. Inflorescences single or paired, cymose, 1–15 cm long, bracts ovate, 0.3–0.4 cm long, sericeous inside, glabrous outside. Flower sub–sessile: calyx slightly shorter than the corolla tube, lobes, 3–4 mm long at anthesis, glabrous inside, sericeous outside; corolla yellow or white, tubular, outside sericeous, inside sericeous at throat, tube widened in the middle, lobes ovate-deltoid, with narrow sinuses, 2.5–3 mm long; stamens subsessile, anther with a long appendage; ovary subglobose, 4-sulcate, glabrous; style 0.3–0.6 mm long; stigma conical. Fruit subglobose, entirely covered by the calyx; nutlets almost 1.5 mm diam.
Venezuela (Bolívar), Brazil (Amapá, Amazonas, Pará); also USA (Florida), Bahamas, Venezuela, eastern Brazil.
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Annual herbs up to 50 cm long, usually cinereous; stems erect or decumbent, sericeous, trichomes appressed. Leaves: petiole slender, 0.4–2.4 cm long; lamina elliptic, obovate or broadly oblanceolate, 1–6 × 0.3–2 cm, apex acute, mucronate, base attenuate, margin entire, both surfaces sericeous. Inflorescences terminal or axillary, peduncle 1–3 cm long, slender scorpioid cymes, mostly geminate or ternate, bractless, up to 10 cm long, sericeous. Flower subsessile: calyx deeply lobed, lobes unequal, lanceolate to linear, about 2/3 as long as corolla tube; corolla white, tube 1–1.4 mm long, throat yellow, lobes spreading ovate with rounded sinus, < 0.5 mm long; stamens subsessile, anthers ovate with a small apical appendage, free; ovary about 0.3 mm diam., style lacking; stigma sessile forming with the ovary a blunt cone. Fruit: depressed-globose, 4-lobed, strigose; nutlets up to 1 mm long.
Venezuela (Amazonas, Bolívar, Delta Amacuro), Guyana, Brazil (Pará, Roraima); also West Indies and from Southern United States to Argentina.
not designated; no original material found.
The only species known from the Guianas that would agree with Meyer’s description is
I want to thank the editor Sandy Knapp for her patience with my struggle with the format. I am indebted to the curators of the herbaria cited who made it easy to get loans, or to work in the collection in their care or who provided scans of types. I want to thank Ingrid Lin (