Rhizophora mucronata var. alokii P.Ragavan, 2015

Ragavan, P., Mohan, P. M., Jayaraj, R. S. C., Ravichandran, K. & Saravanan, S., 2015, Rhizophora mucronata var. alokii - a new variety of mangrove species from the Andaman and Nicobar Islands, India (Rhizophoraceae), PhytoKeys 52, pp. 95-103 : 96-98

publication ID


persistent identifier


treatment provided by

PhytoKeys by Pensoft

scientific name

Rhizophora mucronata var. alokii P.Ragavan

var. nov.

Rhizophora mucronata var. alokii P.Ragavan var. nov.


India. North Andaman : Austin Creek, mangrove forest (Fig. 2A View Figure 2 ), 12°52'36.9"N, 92°50'40.2"E, 3 April 2014, leg. P. Ragavan, PBL 31001 View Materials and 31002 (holotype: PBL) GoogleMaps .

Tree: columnar to spreading, height to 20 m, evergreen (Fig. 2A View Figure 2 ). Bark: dark brown, friable, fissured horizontally (Fig. 2C View Figure 2 ). Roots: both stilt roots and aerial roots growing from lower branches, stilt roots are highly conspicuous arching above ground to 2 m (Fig. 2B View Figure 2 ). Leaves: simple, opposite, green to dark green, elliptical to broadly elliptical (Fig. 2D, E View Figure 2 ), laterally folded, underside with numerous dark spots, 7-13 × 4-8.5 cm, length to width ratio averaging 1.69 (not greater than 1.8), apex obtuse with pointed mucro, 0.4-0.5 cm long (Fig. 2F View Figure 2 ), base cuneate, margin entire; petiole green, 1.5-3 × 0.3-0.5 cm. Inflorescences: axillary, 2-6 flowered (Fig. 2G View Figure 2 ); bract and bracteoles minute (Fig. 2H View Figure 2 ); peduncle 2-3.5 × 0.3-0.5 cm; pedicel stout; Mature flower: ellipsoidal, creamy white (Fig. 2I View Figure 2 ), 1.4-1.6 × 0.7-0.9 cm, length to width ratio ca. 1.87, cross section slightly four-sided (Fig. 2J View Figure 2 ); calyx lobes 4, thicker than Rhizophora mucronata , yellowish white, apex acute; petals 4, thick, leathery, folded laterally, creamy white, velvety and hairy on the margin (Fig. 2L, N View Figure 2 ), 0.9-1.1 × 0.3-0.4 cm; stamens 4, 0.5-0.7cm long (Fig. 2M, N View Figure 2 ); style bilobed (Fig. 2O View Figure 2 ), 0.8- 0.12 cm long, seated on four sided domed ovary (Fig. 2P View Figure 2 ). Mature fruits: pear-shaped, brown, 4-5 × 2.5-3.5 cm, calyx persistent with erect lobes (Fig. 2Q View Figure 2 ). Mature hypocotyls: 40-60 cm long, green, tip pointed, 1.5-1.7 cm wide at widest point (Fig. 2K View Figure 2 ); plumule green, 2-3 cm long.


Rhizophora mucronata var. alokii is currently known only from Austin Creek, North Andaman, India.

Habitat and ecology.

It grows in a mangrove forest along the banks in an intermediate estuarine position in association with Rhizophora apiculata , Rhizophora mucronata and Ceriops tagal .


Flowering December to March; fruiting April to July.


Named in honour of Dr. Alok Saxena (Principal Chief Conservator of Forests) for his inspiration and his outstanding contribution to mangrove conservation in the ANI.

Conservation status.

Rhizophora mucronata var. alokii was collected only from Austin Creek (North Andaman Islands). At this site ca. 15 individuals were observed and hence it is assumed to be rare. At present, until further areas can be sampled the species can be accessed as "Data Deficient" (DD), using the criteria of IUCN (2001).