Caperonia maracaibensis Külkamp & Cordeiro, 2021

Külkamp, Josimar, Iganci, João R. V., Cordeiro, Inês & Baumgratz, José Fernando A., 2021, New species and occurrences of Caperonia (Euphorbiaceae) for South America, Phytotaxa 529 (1), pp. 86-92 : 89-90

Caperonia maracaibensis Külkamp & Cordeiro , sp. nov. ( Fig. 3 )

Type:— VENEZUELA. Zulia: Colon, Concha , en pantano adyacente al final de la carretera (Caño Concha), 11 May 1978, G.S. Bunting & P.A. Drumond 6337 (holotype: NY [NY00640176]!) .

Diagnosis:— Caperonia maracaibensis is similar to C. zaponzeta by its prickly stem and pistillate flowers with 5 equal sepals, but differs by its leaves with abaxially prickly midrib, sepals of the staminate flower pubescent abaxially, petals of staminate flower pubescent abaxially, staminal column ca. 0.8 mm long, 10 stamens, and 9–15-laciniate styles (versus leaves without abaxially prickly midrib, glabrous sepals and petals, staminate column ca. 2 mm long, 9–10 stamens, and styles more than 20-laciniate).

Description:—Herb, ca. 1.2 m tall; internodes 2–5 cm long, stem striated longitudinally, with prickles 0.4–0.9 mm long and simple trichomes at the apex of branches. Stipules ca. 0.25 × 0.1 cm, triangular, ciliate. Leaves: petiole 2– 5 mm long, with prickles; blade 8.9–17.8 × 1.3–3.2 cm, lanceolate, base rounded to truncate, apex acute, penninerved, secondary veins 10–22; indumentum of simple and malpighiaceous trichomes, and short prickles on midrib on the abaxial surface. Inflorescences 8.7–16 cm long, bracts ca. 2 × 1 mm, lanceolate, ciliate; axis with simple and glandular trichomes; staminate flowers 28–41, 4.7–5.1 mm diam., pedicel ca. 1.4 mm long, articulated at the base; sepals 5, 2.4–2.8 × 1–1.1 mm, equal, lanceolate, base fused, apex acute, margin entire, abaxial surface pubescent; petals 5, heteromorphic, 3 of them obovate, 2.9–3.1 × 1.9–2 mm, adnate to the base of staminal column, the other 2 lanceolate, 0.45–0.5 × 0.28–0.35 mm, adnate to the middle of staminal column, with simple trichomes on the abaxial surface; stamens 10, staminal column ca. 0.8 mm long, glabrous, anthers of the external whorl sessile, pistillode globose; pistillate flowers (in bud) with 5 equal sepals, ca. 3.3 × 2.1 mm, lanceolate, base fused to the receptacle, apex acute, margin entire, both surfaces with simple trichomes; petals 5, ca. 3 × 1.9 mm, obovate; ovary with simple and glandular trichomes; styles ca. 1.5 mm long, 9–15 laciniate, glabrous. Fruit and seeds not seen.

Distribution and habitat:— Caperonia maracaibensis is only known from its type collection in northwestern Venezuela, near Maracaibo Lake ( Fig. 2 ). According to Huber & Oliveira-Miranda (2010), the region presents semideciduous forests interspersed with wetlands, where the type specimen was collected.

Conservation status:— Caperonia maracaibensis is Data Deficient (DD) for conservation status assessment ( IUCN 2013), but we believe that urbanization, touristic activities, and habitat conversion in the region are serious threats to C. maracaibensis .

Phenology:—Flowering and fruiting in May.

Etymology:—The epithet “ maracaibensis ” is a reference to the Maracaibo Lake region, where this new species is found.

Notes:—This new species must be included in Caperonia sect. Aculeolatae due to its prickly stem ( Fig. 3B ). The type collection of C. maracaibensis was misidentified as C. heteropetala Didrichsen (148: 1857), but the short prickles and the absence of glandular trichomes in the vegetative structures distinguished the new species. Additionally , C. heteropetala is endemic to the coastal region of southeastern and northeastern Brazil ( Külkamp 2020). Three other species of Caperonia are recorded in Venezuela, C. castaneifolia , C. neglecta and C. palustris ( Table 2 ), but are not endemic to that country ( POWO 2019). In Table 2 also are presented the morphological characteristics that differentiate Caperonia species occurring in Venezuela.

Figures

FIGURE 2.—Distribution map of Caperonia amarumayu (black star), C. maracaibensis (black square), C. zaponzeta (white circles (previous records) and black circles (new records)).

FIGURE 3.—Caperonia maracaibensis. A. Holotype of Caperonia maracaibensis. B. Prickles present in the section Aculeolateae. C. Inflorescence.