India. Kerala, Palakkad district, Kollengode forest range, Nenmeni, Vengappara 10°34'33.6"N, 76°42'47.1"E, 160 m a.s.l., 20 September 2021, Suresh V., V.S.A. Kumar & Arya S., 2077 (holotype UCBD! isotype UCBD!).

Figure 1. 

Polycarpaea ebracteata A habit B flower C flower bud D stipule E, F sepal G petal H gynoecium I capsule J seed. Photos by Arya Sindhu.

Polycarpaea ebracteata is morphologically similar to Polycarpaea corymbosa in terms of having prominent villous stem nodes and shape of petals but differs with respect to stipules (short, ovate less than 1mm, vs. lanceolate, long, 5 mm) bracts (absent vs. present), bracteoles (absent vs. present), sepals (ovate, acute at apex, not membranous vs. lanceolate, acuminate apex, hyaline, membranous), petals (dark brown, ovate-elliptical vs. whitish-pink, broadly ovate), stamens (filament reduced, 0.1 mm vs. filaments equal to the length of anther 1 mm), capsule (style not persistent, tips curved vs. style persistent, tips not curved) and seeds (3–4 or rarely 2, yellow, ovate vs. 5–13, brown, reniform).

Figure 2. 

Polycarpaea ebracteata A habit B flower C stipule D, E sepal F petal G gynoecium H capsule I seed. Illustration by Ambika Viswanathanpillai.

Annual herbs, erect or sub-erect, branched at base, 2.5–8 cm high. Stem terete, densely villous, nodes green, swollen, internodes ca. 5 mm long. Leaves whorled or verticillate, sessile, linear, green, 0.7–0.9 cm long, base cordate, margins smooth, apex acute or acuminate, surface glabrous, blade 1-veined, prominent on abaxial side; stipules scarious, ovate-obovate, (0.2–0.8 × ca. 0.6 mm), margins entire, acute, not nerved, yellowish or greenish at the base, white above. Inflorescence terminal, branched cyme, ca. 1.0 cm long; Flowers 2.2–2.6 mm long; Bracts absent. bracteoles absent; pedicels 1.0–1.3 mm long, green, villous. Sepals 5, free, ovate (1.3–1.4 × ca. 0.7 mm), entire at the margin, acute or obtuse at apex, white, non-membranous base round, midrib not prominent. Petals 5, ovate (0.1–0.3 × 0.1–0.3 mm), margins entire, oblong to round at apex, partially enclosing the ovary, 1/4 as short as sepals, dark red-brown. Stamens 5, forming a ring with petals and encircling the ovary, ca. 0.2 mm long; anthers yellow, oblong, basifixed. Ovary 1-loculed, shortly stipitate, spheroidal, 0.3–0.5 × 0.1–0.2 mm, glabrous, placentation free central; style 0.08–0.1 mm, shorter than the ovary, slender; stigma capitate. Capsule ovoid (1.4–1.6 × ca. 0.6 mm), shortly stipitate, 3-valved, breaks along the suture, brownish, scarious along margin. Seeds 3–4 (rarely 2), ovate (0.2–0.3 × 0.1–0.2 mm), yellow with no striations.

Micromorphology of the seed shows that it is round-oblong with a winged margin. The surface has sub parallel striations which are prominent. The striations do not cross each other and the encircling surface of the striations are punctate. Along the margins, the surface has parallel striations (Fig. 7E, F).

Latin prefix e-, without, bractea, bract, and suffix -ata, possession, alluding to absence of bracts, a diagnostic character.

Flowering and fruiting during August – December

The primary habitat of Polycarpaea ebracteata is the hillock terrains in Palakkad district (Granite outcrop in the southern side of Palakkad gap, the largest break in the Western Ghats having an arid climate with seasonal fires, in the state of Kerala). One of the common species that emerges after the initial rain are members of the Genus Polycarpaea, especially Polycarpaea aurea (Wight 1850: 44) Dunn (1915: 65). Polycarpaea ebracteata is seen associated with Allmania nodiflora (L.) R. Br. ex Wight, Indigofera aspalathoides DC. and Fimbristylis cymosa R. Br. (Fig. 8).

The present study could report only three populations each with 15–20 individuals. Since Polycarpaea ebracteata could occur in further sites in SW-India (and India as a whole), we think that further data is required to ascertain the conservation status of the new taxon. As a consequence, the new species is here assessed as DD (Data Deficient) according to the IUCN criteria (IUCN 2021).

Polycarpaea ebracteata India. Kerala, Palakkad district, Kollengode, Cheerani. 12 September 2021, Suresh V. & Alen Alex Philip, 2061 (UCBD!); 20 September 2021, Sojan Jose & Suresh V, 2078 (UCBD!).

India. Kerala, Palakkad district, Nenmara, Ayinampadam, 10°35'29.4"N, 76°34'48.2"E, 140 m a.s.l., 21 September 2021, Suresh V. & Arya S., 2081 (holotype UCBD! isotype UCBD!).

Figure 3. 

Polycarpaea psammophila A habit B inflorescence C internode D flower cluster E flower F bract G bracteole H petal I stamen J sepal K stipule L gynoecium M capsule N seed. Photos by Suresh V.

Polycarpaea psammophila is morphologically similar to Polycarpaea corymbosa with respect to the whorled arrangement of leaves and pilose nature of stem but differs with respect to stipules (linear to lanceolate with acuminate apex vs. lanceolate-ovate, with acute apex), bract (lanceolate-oblanceolate white, exceeding the length of sepal vs. lanceolate-ovate, shorter than the sepal), bracteoles (linear with acicular apex vs. lanceolate with acute apex), petals (ovate – oblate, keeled, dark brown, apex pointed upwards vs. broadly ovate, not keeled, whitish-pink, round at apex), gynoecium (oblate spheroidal, reddish yellow vs. ovate short, green), capsule (four valved vs. three valved) and seeds (20–25 yellowish brown, ovate vs. 5–13, brown, reniform).

Figure 4. 

Polycarpaea psammophila A habit B flower C stipule D bract E bracteole F sepal G petal H stamen I capsule J seed. Illustration by Ambika Viswanathanpillai.

Annual herbs, erect or sub-erect, 18–25 cm high. Stems terete, densely villous, nodes green, swollen, internodes ca. 1.5–2 cm long. Leaves whorled, sessile, linear-lanceolate, green, 2.3–3.1cm long, base round, margin smooth, daggered in young leaf, apex acute or obtuse abaxial surface glabrous, adaxial surface pubescent along the mid vein; blade 1–2 veined, prominent on abaxial side; stipules prominent, linear to lanceolate, fused at the base (5–8 × ca. 2 mm), base golden yellow with unicellular setae; setae hyaline; margins entire, often bifurcated into two, branches acicular at apex, not nerved, milky white. Inflorescence terminal, irregular, branched lax cyme, ca. 10 cm long; Bracts lanceolate-oblanceolate, exceeding the length of the sepal (2.0 – 2.3 × ca. 0.3 mm); base smooth, margin entire, apex acuminate. Bracteole 1.3mm linear with acicular apex, holding the bracts in position. Flowers 8–10 per cyme, 4–5.5 mm long; pedicels 1.0–1.3 mm long, green villous. Sepals 5, free, obovate-oblanceolate (2.3–2.6 × ca. 0.7 mm), entire at the margin, acute or obtuse at apex, white, non-membranous base round, midrib faint. Petals 5, ovate-oblate (1–1.3 × 1.1–1.3 mm), margin entire, keeled, pointed upward at apex, partially or completely enclosing the ovary, 1/2 as short as sepals, dark red-brown. Stamens 5, forming a ring with petals and encircling the ovary, ca. 0.3 mm long; anthers yellow, oblong, basifixed. Ovary 1-loculed, shortly stipitate, spheroidal, reddish-yellow 1.2–1.3 × 1–2 mm, glabrous, placentation free central; style 0.2–0.3 mm, shorter than the ovary, often very reduced and slender; stigma capitate. Capsule oblate-prolate (1.4–1.6 × ca. 0.6 mm), style persistent, shortly stipitate, 4-valved, breaks along the suture, brownish, scarious along margin. Seeds (20–25) ovate (0.2–0.3 × 0.1–0.2 mm), yellowish brown with striations.

Micromorphology of the seed exhibits a sub-orbicular shape with striations that are not parallel and cross each other towards the margin. The epidermal cell pattern is angular to spheroidal. Seed margin is entire and along the margin the cells are rectangular shaped (Fig. 7G, H).

Flowering and fruiting during August– December.

Greek psammos, sand, and philios, loving, alluding to exclusive habitat of sandy marginal zones of granite hills.

The primary habitat of Polycarpaea psammophila is the hillock terrains in Palakkad district along the sandy margins. It is seen associated with Tephrosia purpurea (L.) Pers., Parasopubia delphiniifolia (L.) H.-P. Hofm. & Eb. Fisch. and Glinus oppositifolius (L.) A. DC. (Fig. 8).

The current study is based on two different populations ranging from 50–80 individuals. We believe that further data is needed to determine the conservation status of Polycarpaea psammophila because it could be found in other locations in SW-India (or India as a whole). As a result, according to IUCN criteria, the new species is classified as DD (Data Deficient) (IUCN 2021).

India. Kerala, Palakkad district, Nenmara, Vallangi, 12 September 2021, Suresh V. & Alen Alex Philip, 2065 (UCBD!); 21 September 2021, Sojan Jose & Kumar V.S.A., 2083 (UCBD!).

India. Kerala, Palakkad district, Kuthanur, Chedukamala 10°41'42.6"N, 76°31'06.3"E, 150 m a.s.l., 20 October 2021, V.S.A Kumar, Suresh V & Arya S., 3010 (holotype UCBD! isotype UCBD!).

Figure 5. 

A habit B flower bud C internode D flower E bract F stipule G sepal H petal I stamen J gynoecium K capsule L seed. Photos by V.S.A. Kumar.

Polycarpaea barbellata is morphologically similar to Polycarpaea aurea with respect to yellow-orange color of sepals but differs with respect to stipules (oblong, parted into 3 with a long acicular structure in the center and other two parts barbellate vs. lanceolate parted into 2, free, with no central structure), Inflorescence (dense cyme vs. lax cyme), bract (linear, white, acicular apex vs. lanceolate-ovate, greyish-brown, acuminate apex), bracteoles (Capillaceous with acicular apex vs. ovate lanceolate with acute apex), petals (wedge shaped, whitish-lilac vs. broadly ovate-oblong, yellowish-brown), Gynoecium (spheroidal, yellowish green reduced vs. conical, short yellow), capsule (style not persistent, tip not recurved, 2–3 seeded vs. style persistent, tip recurved, 5–many seeded).

Figure 6. 

Polycarpaea barbellata A habit B flower bud C flower D capsule E bract F stipule G petal H stamen I gynoecium J seed. Illustration by Ambika Viswanathanpillai.

Annual herbs, erect or sub-erect, branched from the base 10–15 cm high. Stem terete, sparsely villous, nodes red swollen, internodes 1.5–2 cm long. Leaves whorled, sessile, lanceolate-oblanceolate, green, 1.3–2.1cm long, base round, margin smooth or wavy, apex acute or acuminate, abaxial surface glabrous, adaxial surface pubescent; lamina 1–2 veined, prominent on abaxial side; stipules prominent, oblong, parted into 3 (2 equal barbellate parts), central part has a long acicular structure ca. 1 mm long, fused at the base (1–1.2 × ca. 0.4 mm), base golden yellow, smooth; margin entire, apex acicular, milky white. Inflorescence terminal, branched regular dense cyme, ca. 4.5 cm long; Bracts linear – lanceolate, 0.8 – 1.0 mm, white, equal or sub-equal to the length of the sepal; base smooth, margin entire, apex acicular. Bracteole capillaceous with acicular apex, holding the bracts in position. Flowers 4–6 per cyme, 3.5–3.8 mm long; pedicels 1.5–2.3 mm long, green villous. Sepals 5, fused at base, ovate (1–1.2 × ca. 0.8 mm), entire at the margin, acute to obtuse at apex, white, non-membranous base round, midrib faint. Petals 5, broadly wedge shaped (0.5–1 × 0.5–0.6 mm), margin entire, completely enclosing the ovary, 1/3 as short as sepals, whitish-lilac. Stamens 5, forming a ring with petals and encircling the ovary, ca. 0.9 mm long; anthers yellow, ovate, basifixed. Ovary 1-loculed, shortly stipitate, spheroidal, yellowish green, 1.2–1.3 × 1–2 mm, glabrous, placentation free central; style 0.01–0.03 mm, shorter than the ovary; stigma capitate. Capsule oblate-prolate (1.4–1.6 × ca. 0.6 mm), shortly stipitate, style not persistent, tip not recurved, 3-valved, breaks along the suture, brownish, scarious along margin. Seeds (2–3) ovate (0.1–0.15 × 0.1–0.2 mm), yellow with striations.

Micromorphology of the seed is ovate-sub-orbicular in its outline with depressions all over the seed surface. The margin is entire and the epidermal cell pattern is faintly angular. Striations are also faint (Fig. 7I, J).

Figure 7. 

SEM of seeds (P. corymbosa) A seed B seed surface C, D P. palakkadensis E, F P. ebracteata G, H P. psammophila I, J P. barbellata K, L P. aurea.

Flowering and fruiting during August-December.

Latin barba, stiff hairs, suffix ella, diminutive, and -ata, possession, alluding to barbellate nature of stipules, a diagnostic character.

The primary habitat of Polycarpaea barbellata is the hillock terrains in Palakkad district (Kerala granite outcrop in the northern side of Palakkad gap, the largest break in the Western Ghats having an arid climate with seasonal fires). Polycarpaea barbellata is also seen associated with Polycarpaea corymbosa, Fimbristylis sp. and Indigofera enneaphylla (Fig. 8).

Figure 8. 

Distribution map of Polycarpaea ebracteata, P. psammophila and P. barbellata.

The present study could report two populations with 20–35 individuals each. We consider that further evidence is needed to determine the new taxon’s conservation status because Polycarpaea barbellata could be found in other regions in Southwest (and India as a whole). As a consequence, the new species is now categorized as DD (Data Deficient) by the IUCN (IUCN 2021).

India. Kerala, Palakkad district, Kuzhalmannam, Kariyanchirachola, 2 November 2021, Suresh V. & Sojan Jose, 3077 (UCBD!); 10 November 2021 Alen Alex Philip & Suresh V., 3084 (UCBD!).

In India, the genus Polycarpaea is represented by seven species (Arya et al. 2021). The proposed three new species are closely allied to Polycarpaea corymbosa (Linnaeus 1753: 205) Lamarck (1792: 129) and Polycarpaea aurea that has wide distribution along with P. palakkadensis. The new species also resembles Polycarpaea palakkadensis superficially but differs distinctly with respect to characters summarized in Table 1.