Maracanthus kuijtii J. S. Murillo, Carmona, F. J. Roldán & Alzate, 2025

4. Maracanthus kuijtii J. S. Murillo, Carmona, F. J. Roldán & Alzate sp. nov.

Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4 , 5 View Figure 5

Type.

COLOMBIA – Santander • Municipio de Floridablanca, Corregimiento La Corcova, estación experimental El Diviso ( CDMB), bh-MB; 7°06’44”N, 73°01’48”W [7.112, -73.030]; 2300 m; 21 Oct. 2001; fl.; Alzate F., López J. M. & López J. 1191; holotype: HUA [ HUA 134843 About HUA ] GoogleMaps .

Diagnosis.

Maracanthus kuijtii differs from the remaining species of the genus by the combination of glabrous twigs, spike peduncles terete, glabrous, without furfuraceous, sharp edges and with a rachis glabrous, bearing more than 12 flowers.

Description.

Stem hemiparasites. Haustorium not seen. Shoots percurrent, branches erect, young branches ancipitate, keeled, very soon covered by griseous cork and profusely lenticellate. Internodes terete when mature, 1.1–4 cm long, 1.2–5.4 mm diam., glabrous, the vertices not covered by furfuraceous indumentum; nodes slightly swollen. Leaves opposite, black in sicco. Petioles 4–6.6 mm long, 1.3–1.6 mm diam., slender, adaxially flattened, abaxially rounded. Leaf blades elliptic, 3–6 × 14– 2.8 cm, coriaceous, glabrous on both surfaces, base cuneate, apex obtuse, margin entire, slightly covered with furfuraceous cork; venation camptodromous, midvein raised and keeled in abaxial surface, primary and secondary veins slightly raised in both surfaces. Inflorescences a spike, erect, axillary, 1 per axil, peduncles 5.4–6.8 mm long, 0.7–1.1 mm diam., glabrous, slightly quadrangular, rachis fleshy, glabrous, bearing up to 44 flowers in four series of distichous pairs; flowers sunken in foveae accompanied by a basal scale-like bract of ca 0.5 mm long; bracteoles paired, conspicuous, beyond the margin of the fovea, navicular-elliptic, ca 0.6 × 0.5 mm. Flowers inserted at 90 ° to the axis when mature, sessile, straight, ca 3.5 mm long, 6 - merous, bisexual. Corolla in preanthesis rounded apically; petals dimorphic, 2.4–2.5 × 0.7–0.9 mm, margin entire. Androecium epipetalous. Stamens dimorphic, the longer ones in petals with obtuse apex, the smaller ones in petals with acute apex; filaments 0.8–1 mm long (in longer stamens), ca 0.4 mm long (in shorter stamens); anthers 4 - loculate, dehiscence longitudinal, 0.7–1 mm long, 0.8–0.9 mm diam. in longer stamens, 0.8–0.9 mm long, 0.9–1 mm diam. in shorter stamens; connective horn 0.2–0.3 mm long, with rounded apex in longer stamens, 0.3 mm long, with the acute apex in shorter stamens. Pollen triangular-concave, oblate, syncolpate. Ovary partially sunken in the cavity of the rachis, 0.7–1.1 mm long, 1.3–1.4 mm diam., obconical. Calyculus 0.2–0.3 mm long, membranous, smooth. Style 1.7–1.8 mm long, 0.3 mm diam. in proximal portion, straight; stigmatic region 0.3 mm diam., as an extension of the style, ensiform and micropapillate. Fruits and seeds not seen.

Palynology.

Monad; amb triangular-concave; oblate; isopolar; symmetry radial; syncolpate (tricolpate); exine tectate; columellae (0.6–0.9 μm length); homobrochate; muri width 0.3–0.5 μm, brochi width 0.9–1 μm, lumina width 0.6–0.8 μm; equatorial view length 23.3 μm (21.8–24.8, n = 3); equatorial view width 40.5 μm (37.4–44.4, n = 3); polar view length 36.6 μm (33.5–38.9, n = 10) (Fig. 3 View Figure 3 ).

Distribution, habitat, and phenology.

Maracanthus kuijtii is endemic to the Eastern Cordillera of the Colombian Andes, collected only at the department of Santander, at elevations close to 2300 m (Fig. 5 View Figure 5 ). This species grows in remnants of Andean forest near plantations of Cupressus lusitanica Mill. and Pinus patula Schltdl. & Cham. , and agricultural areas. This mistletoe has been collected parasitising a 12 - meter tall Zanthoxylum melanostictum Schltdl. & Cham. ( Rutaceae ) tree. The only known specimen of M. kuijtii to date was flowering in October.

Etymology.

The epithet honours Job Kuijt (1930 –), taxonomist and mistletoe specialist, who has contributed notably to our knowledge of parasitic plants, especially mistletoes.

Preliminary IUCN conservation assessment.

Maracanthus kuijtii is only known from the type specimen, which was collected in an Andean Forest, a region severely threatened by agricultural activities. Additional studies are required to obtain more information about this mistletoe, especially regarding its demography, host range, distribution, and ecology. We suggest considering this species as “ Data Deficient ” [DD], according to the IUCN Red List Categories and Criteria ( IUCN 2012), awaiting the results of future studies.

Notes.

The species here described belongs to the genus Maracanthus , distinguished by leaf veins without stellate fibres (Fig. 4 View Figure 4 ), conspicuous bracteoles, flowers with all fertile anthers and filaments, and triangular and syncolpate pollen, lacking circular depressions ( Kuijt 1976, 2013; Feuer and Kuijt 1985; Kuijt and Hansen 2015; Grímsson et al. 2017). The remaining genera of neotropical Loranthaceae with monadic spikes differ from Maracanthus by the following characters: Dendropemon (Blume) Rchb. in having flowers alternating fertile stamens with staminodia; Oryctanthus in having stellate fibre bundles in the mesophyll and pollen with circular depressions alternate to colpi; Oryctina in having sessile anthers and minute bracteoles, and Cladocolea in lacking bracteoles accompanying the flowers ( Kuijt 2013; Kuijt and Hansen 2015).

Among the species of the genus, M. kuijtii resembles M. badilloi . However, M. badilloi has entirely furfuraceous twigs and spikes less than 1 cm long, bearing 4–8 flowers. In contrast, M. kuijtii has twigs that are entirely glabrous and spikes that are more than 1 cm long, 12–44 flowers. To date, M. badilloi is endemic to Venezuela, occurring at the Venezuelan Coastal Range (Cordillera de la Costa) on slopes towards the sea and in the Venezuelan Andes at the Cordillera de Mérida. In contrast, M. kuijtii occurs in the Colombian Andes at the Eastern Cordillera (Cordillera Oriental) on slopes towards the valley of the Magdalena River (Fig. 5 View Figure 5 ).

Maracanthus kuijtii can be differentiated from the other four species of the genus by traits on its inflorescence, indumentum, and floral morphology, as shown in the taxonomic key provided above.