Commelina pseudomonosperma (Kuntze) L.M.Campb.

Commelina pseudomonosperma (Kuntze) L.M.Campb. View in CoL

Figs 11 View Fig , 13 View Fig ; Table 3 View Table 3

Commelina pseudomonosperma (Kuntze) L.M.Campb. View in CoL (Campbell in Hokche et al. 2008: 714). – Athyrocarpus pseudomonosperma Kuntze ( Kuntze 1898: 319) View in CoL . – Phaeosphaerion pseudomonosperma (Kuntze) Steyerm. ( Steyermark 1951: 152) View in CoL .

Etymology

The epithet derives from the combination of the Ancient Greek ʻ ψευδής ʼ ( pseudḗs, meaning ʻlying, falseʼ) + ʻ μόΝΟς ʼ (ʻ mónos ʼ, meaning ʻalone, only, sole, singleʼ) + ʻ σπέρμα ʼ ( spérma, meaning ʻseedʼ), in reference to its seeds fused to the fruit wall and septa, giving the impression of being a single seed.

Type material

BRAZIL – Mato Grosso • prov. Mato Grosso, in swamp forest near Vila Maria do Paraguai [Cáceres]; Jul. 1892; fr.; O. Kuntze s.n.; lectotype: NY [ NY00247408 ]!, designated by Hassemer (2020) .

Material examined

BRAZIL – Mato Grosso • Itaúba, Resgate de Flora da Linha de Transmissão da UHE Colíder ; 3 Jul. 2017; fl., fr.; M.E. Engels & J.A.O. Freitas 5752; HERBAM, MBM, NX, RB, TANG • Serra do Roncador, vicinity of Nova Xavantina , margins of Rio Mortes ; 25 Sep. 1964; fr.; G.T. Prance et al. 59106; MO, NY, US, S .

Description

Herbs 30–90 cm tall, scrambling to prostrate, perennial, robust, terrestrial to paludal. Roots fibrous, thin. Rhizome short. Stems monomorphic, prostrate to scrambling, branched; internodes 0.8–9.1 cm long, distally shorter, light green to green, glabrous, with a line of acicular hairs opposite to the leaves, hairs hyaline or rusty to rusty-brown. Leaves distichously-alternate, evenly distributed along the upper part of the stem, pseudopetiolate; sheaths 1–2.2 cm long, light green to light green longitudinally striated with green to dark green, glabrous, sometimes speckled with magenta to vinaceous along the margin, margin upright, glabrous to setose, with a line of setose hairs opposite to the leaves, hairs acicular, light brown to rusty; pseudopetiole 1.4–5.8 mm long; blades 5.6–10.8 × 1.2–3.6 cm, lanceolate to ovate, sometimes elliptic, straight, thinly chartaceous to chartaceous, adaxially dark green to green, abaxially light green, glabrous on both sides, sometimes abaxially inconspicuously scabrid along the midvein at base, hairs acicular, hyaline, base asymmetric to strongly asymmetric, one side cuneate the other round, margin slightly revolute, glabrous to scabrid with prickle-hairs, apex acuminate to long-acuminate; midvein conspicuous, adaxially impressed, abaxially prominently obtuse, secondary veins 3–4 pairs, adaxially conspicuous, abaxially conspicuous, becoming more conspicuous on both sides when dry. Synflorescence composed of a main florescence plus 1–6 co-florescences, axillary and terminal. Inflorescences terminal or apparently so, peduncle 0.3–0.9 cm long, shorter than ½ length of the spathe, straight, glabrous to puberulous with hook-hairs, sometimes with a line of acicular hairs opposite to the spathe, hairs hyaline; spathe 1.9– 2.3 × 2.1–3.4 cm, very widely ovate to depressed ovate, patent to the peduncle, pale greenish-yellow to yellowish-green, generally suffused with magenta to vinaceous along the margin, internally conspicuously mucilaginous, base only basally connate, splitting open and marcescent in fruit, truncate to subcordate, externally glabrous, rarely with occasional hook-hairs, hairs hyaline, margin repandous, apex acuminate, slightly falcate, veins 4–5 pairs, conspicuous, becoming more conspicuous when dry; upper cincinnus developed, 1–2-flowered, flowers mainly staminate, rarely bisexual, peduncle 1.6–3.3 cm long, exserted, straight to gently decurved at pre-anthesis and anthesis, gently recurved at post-anthesis and fruit, sparsely to densely puberulous with minute hook-hairs, hairs hyaline; lower cincinnus 2–5-flowered, flowers mainly bisexual, sometimes staminate, peduncle 0.7–1.6 cm long, thickened in fruit, glabrous to sparsely puberulous with minute hook-hairs. Flowers chasmogamous, strongly zygomorphic, enantiostylous (style gently dislocated to the opposite side to the medial stamen); floral buds 2.6–5.8 × 1.4–4.2 mm, obovoid, light green to white, glabrous; pedicel 3.2–6.9 mm long, deflexed in bud and at anthesis, reflexed and elongating in fruit, light green, sparsely puberulous with minute hook-hairs, hairs hyaline; sepals hyaline, early deciduous in fruit, dorsal sepal 2.5–3.1 × 1.5–2.1 mm, elliptic, concave, glabrous, apex obtuse, lower sepals 4.9–6.1 × 3.2–4.6 mm, shortly-clawed, connate up to mid-length, oblique-obovate, concave, glabrous, apex obtuse; paired petals 0.5–0.8 × 0.4–0.5 cm, clawed, claw 2.3–3.9 mm long, white to pale lavender to light pink, limb 2.9–4.4 × 3.4–4.9 mm, widely rhombic-reniform to reniform, pale lavender to light pink, base asymmetric, cordate, apex truncate to slightly emarginate, medial petal 5.1–6.3 × 2.2–3.2 mm, sessile, spathulate to oblanceolate, entire, cucullate, concolourous with the paired petals, opaque, glabrous on both sides, apex round; staminodes 2–3, medial staminode completely absent or greatly reduced and lacking the antherode, filaments 2.6–3.3 mm long, arcuate-decurved, white, base pale greenish-yellow, apex tan-coloured, antherodes 0.3–0.5 × 0.2–0.3 mm, subtrapezoid, pale yellow, minute pollen sacs between the upper and lower lobes absent, not apiculate between the upper lobes, upper lobes reduced, smaller than the lower, lower lobes reduced; lateral filaments 4.9–6.1 mm long, straight to very gently sigmoid, apex gently recurved, white, base pale greenish-yellow, apex tan-coloured, anthers 0.4–0.6 × 0.7–1.2 mm, held near the medial stamen, subcordate to cordate, yellow, connective yellow, pollen pale yellow, drying yellow; medial filament 4.7–6 mm long, straight or arcuate-recurved, suddenly decurved near the apex, white, base pale greenish-yellow, apex tan-coloured, anther 1–1.3 × 0.8–1.2 mm, held with the lateral anthers, widely sagittate, straight to slightly curved, yellow, connective saddle-shaped, pale yellow, anther sacs not appressed to each other, connective yellow, pollen pale yellow, drying yellow; ovary 0.8–1.1 × 0.7–1 mm, 3-carpellate, 5-ovulate, widely ellipsoid to subglobose, greenish-yellow to light green, smooth, puberulous with glandular microhairs, style 5.1–6.7 mm long, exceeding the stamens, base cylindric, straight to very gently sigmoid, white, base pale greenish-yellow, apex tan-coloured, deciduous in fruit, stigma truncate, tan-coloured. Capsules 2–4 per spathe, 4.8–6.2 × 4.6–5.1 mm, widely obovoid, short-stipitate, stipe 0.8–1.2 mm long, fruit wall thin, crustaceous, apex round, not constricted between the seeds, pearly-white to silvery when mature, shiny, smooth, 3-locular, indehiscent, dorsal locule 1-seeded, ventral locules 2-seeded. Seeds monomorphic, 2.2–4.3 × 1.6–2.7 mm, the dorsal seed slightly larger than the ventral ones, all seeds adnate to the fruit wall and septa forming a dispersal unit, ellipsoid to triangular-ellipsoid, dorsally slightly flattened, ventrally pyramidal, not cleft towards the embryotega, dark grey to black, testa inconspicuously foveolate, non-farinose, embryotega semilateral, inconspicuous, with a prominent apicule, hilum linear, longer than ½ the length of the seed.

Distribution

Commelina pseudomonosperma is currently endemic to the State of Mato Grosso, Brazil ( Fig. 11 View Fig ). Campbell (2008) erroneously reports C. pseudomonosperma for Venezuela based on misidentified specimens of C. obliqua .

Ecology

It grows in the understory in seasonally dry forests in the Amazon Forest and Pantanal biomes, between 170 and 280 m a.s.l. ( Fig. 11 View Fig ).

Phenology

It was found in bloom and fruits in July.

Vernacular names

Trapoeraba rosa ( Brazil), manobi-pitanguí ( Brazil), andacá-pitanguí ( Brazil), Anda ka’a pytãngy ( Brazil – Guarani).

Conservation

Commelina pseudomonosperma has a wide EOO (117 138 km 2) but a very narrow AOO (ca 16 km 2), being known from only three localities and two collections. Thus, we suggest it should be considered Endangered [EN, B1ab(i, ii, v)], following the IUCN (2012) criteria and the IUCN Standards and Petitions Committee (2024) recommendations.

Remarks

Campbell (2008) transferred Athyrocarpus pseudomonosperma to Commelina but provided no explanation or rationale for her decision. This decision was most likely based on her lack of knowledge of the group, which led to her not only misapplying the newly presented combination but also greatly expanding the distribution of this narrowly endemic species. Further confusion was caused by Hassemer (2020), who reduced C. pseudomonosperma and C. obliqua (as C. rufipes var. glabrata ) to mere synonyms of C. rufipes . These mistakes have been perpetuated by Aona & Amaral (2020), who retained C. pseudomonosperma (as A. pseudomonosperma ) and C. obliqua (as C. rufipes var. glabrata ) as a synonym of C. rufipes .

Despite the obvious similarity between these species (see Remarks on C. obliqua and C. rufipes ), C. pseudomonosperma can be readily differentiated from them due to its pale lavender to light pink flowers ( Table 3 View Table 3 ), a character unique in the South American species of Commelina and rare in the genus as a whole. Furthermore, it can be differentiated from C. obliqua (the morphologically most similar species) due to its synflorescences axillary and terminal, composed of main florescence plus 1–6 co-florescences (vs terminal and composed of a solitary main florescence in C. obliqua ), spathe light green suffused with vinaceous or purple, margin repandous (vs almost white to light green, margin flat), petals pale lavender to light pink (vs white), medial petal cucullate and lacking a medial constriction (vs margin revolute at mid-length, forming a medial constriction), antherodes subtrapezoid, indistinctly lobed, minute pollen sacs between the upper and lower lobes absent (vs narrowly hastate, distinctly lobed, minute pollen sacs between the upper and lower lobes present), lateral anthers subcordate to cordate (vs elliptic to ovate), style straight to very gently sigmoid (vs sigmoid), and fruits 2–4 per spathe, widely obovoid (vs widely ellipsoid to widely oblongoid) ( Table 3 View Table 3 ).