Murdannia vaginata

Murdannia vaginata View in CoL (L.) G. Brückn. var. glabrisepala Faden, Novon View in CoL 11: 26. 2001, in Dassan., Rev. Handb. Fl. Ceylon 14: 162. 2000. Type: SRI LANKA, Western Province, Colombo district, Muthuraja Wela, Nugape , at the junction of road to Bopitiya and Kandana , N 7º 03’, E 79º51’40’’, sea level, sedge marsh, 30.11.1976 GoogleMaps . R.B. Faden & A. J. Faden 76/419 (holo US barcode 00160794 digital image!). Fig. 3 View Fig

Annual herbs 5–30 cm tall. Stems erect to ascending, glabrous. Roots fibrous, from the base and rarely from the lower nodes touching the soil, to 1 mm thick. Leaves all cauline, distichous to spirally arranged; sheaths 0.5–1.5 cm long, green, maroon towards the base, glabrous with a line of cilia along the fused edges and mouth, clasping the stem; lamina linear-lanceolate, 3–7 × 0.3–0.6 cm, base truncate, entire, apex acute to acuminate, glabrous. Inflorescences terminal and axillary, 1–2 fascicles of 2–6 one-flowered cincinni enclosed in a prominently ribbed, persistent bract; bracts lanceolate, 1–1.5 × 0.1–0.2 cm, base rounded, entire, apex narrowly acute, glabrous; peduncles 5–15 cm long, narrow, erect, glabrous; cincinni 2-noded, 0.9–1.3 cm long, basal segment glabrous, middle segment minutely pubescent towards apex, distal segment the pedicel. Flowers bisexual or staminate; pedicels 4–5 mm long, pubescent, erect in fruit. Sepals 3, lance-ovate, 4–5 × 1.2–1.5 mm at anthesis, 5–6 × 1.5 mm in fruit, free, base slightly rounded, margins entire, apex acute, glabrous on both surfaces, hyaline, pale green, tinted maroon at apex. Petals 3, c. 3 × 2 mm, free, middle petal rhombic and lateral petals elliptic, base acute to obtuse, margins entire, apex acute to obtuse, glabrous on both sides, lavender. Stamens 2, held closely parallel in the centre of the flower in bisexual flower, or symmetrical and divergent in the male flower, 2–2.2 mm long, antesepalous; filaments free, violet, densely hairy towards base; anthers dorsifixed, anther sacs elliptic, bluish-brown, longitudinally dehiscing; pollen ellipsoid, yellow. Staminodes 4, 1 antesepalous, 3 antepetalous, 1.8– 2 mm long; filaments free, glabrous; antherodes hastate, yellow. Ovary 0.8–1 × 0.6–0.8 mm, widely elliptic, green; style c. 1.5 mm long, lavenderwhite, tip slightly curving to one side; stigma white or pale yellow, papillate. Capsules globose to sub-globose, 2.5–3 × 2.5–3 mm, persistent calyx exceeding the length and completely covering the capsule. Seeds 1 per locule, widely elliptic, 2.2–2.6 × 1.7–1.9 mm, cleft towards the embryotega; testa dark brown, scrobiculate with furrows between the ridges, cells alveolate to tuberculate, outer cell layer sloughing off, leaving a finely raised reticulum; hilum linear, c. ½ the length of the seed on a raised ridge; embryotega dorsal, inconspicuous.

Flowering & fruiting: October to December.

Habitat: The species grows in exposed, moist, sandy areas along with Murdannia vaginata var. vaginata ( Commelinaceae ), Utricularia caerulea L., U. uliginosa Vahl ( Lentibulariaceae ), Eriocaulon sp. ( Eriocaulaceae ) and some grasses ( Fig. 4a View Fig ).

Distribution: India and Sri Lanka ( Fig. 4b View Fig ). According to Faden (2001), M. vaginata var. glabrisepala is also found in India. However, the author provided no voucher specimen to support this statement. We have consulted specimens of Murdannia in different herbaria (see materials and methods) but could not find any specimens of M. vaginata var. glabrisepala from India. Ancy and Nampy (2015) and Nandikar and Gurav (2015) also did not mention its occurrence in India. Hence the present report forms an extended distribution of this taxon in India.

Specimens examined: INDIA, Kerala, Kozhikode district, Kakkayam, way to Urakkuzhi waterfalls, N 11º32’12.9’’, E 75º55’01.403’’; 656 m, 06.10.2022, Sreekutty, Harishma, Krishnapriya & Santhosh Nampy, 167995 ( CALI); Ibid., 23.10.2022, Sreekutty T. K GoogleMaps . & Santhosh Nampy 167999, 168000 (CALI).

Conservation status: This variety is so far known only from four locations, one in South India (Kakkayam in Kozhikode district) and three (Karuvakkeni in Batticaloa, Galle and Pedcambra) in Sri Lanka ( Faden, 2001). The Extent of Occurrence (EOO) is c. 85,500 km 2, and the Area of Occupancy is 16 km 2. The present locality in India is on the outskirts of the Malabar Wildlife Sanctuary, and we observed about 250 mature plants there. The habitat is under pressure from tourism and the grazing of animals, which may cause a decline in habitat quality and the number of mature individuals. Since, no information is available on the population size and threat status of this taxon for Sri Lanka, the assessment is done for India only. Because of the restricted distribution and known threat to the habitat in India, the variety is assessed here as Critically Endangered (CR), B2ab (iii,v), according to IUCN Red LIST Categories and Criteria ( IUCN, 2012, 2022).

Notes: Murdannia vaginata is quite distinct among all other species of Murdannia in having a highly reduced inflorescence with fascicles of 1-flowered cincinni with two nodes and a persistent bract on the lower node enclosed in a prominently ribbed, glabrous, bladeless sheath, pubescent pedicels, and one seeded capsule locules. Murdannia vaginata var. glabrisepala differs from var. vaginata by its glabrous sepals, a persistent calyx that completely covers and exceeds the capsule, seeds with dark grey-black testa, scrobiculate with furrows between the ridges, cells of the testa alveolate to tuberculate, and outer cell layer sloughing off and leaving a finely raised reticulum, and hilum c. ½ the length of the seed, on a raised ridge. But in M. vaginata var. vaginata , the seeds are light brown, scrobiculate with shallow furrows between the ridges, cells slightly tuberculate, outer cell layer partially sloughing off, not leaving a finely raised reticulum, and hilum longer than ½ the length of the seed, on a slightly raised ridge ( Fig. 3 View Fig ). Faden (2001) considered M. vaginata var. glabrisepala to be a perennial with relatively thick roots and smooth to alveolate-reticulate seeds. Even though the roots are little bit thick in the present collection, the plants are annual and the seeds are scrobiculate with furrows between the ridges, with the cells of the testa being alveolate to tuberculate. According to Faden (2001), var. vaginata has only bisexual flowers and and stamens held closely parallel in the center of the flower while var. glabrisepala has andromonoecious flowers exhibiting enatiostyly. He further indicated that “enantiostyly [is] present or absent, according to the population”. However, we observed that, both varieties gathered from the same population have andromonoecious flowers and both grow and bloom together in the present location, and no intermediates were found.