Commelina andamanica S.M. Joseph & Nampy, 2013

Nampy, Santhosh, Joseph, Sheba M. & Manudev, K. M., 2013, The genus Commelina (Commelinaceae) in Andaman & Nicobar Islands, India with one new species and three new records, Phytotaxa 87 (2), pp. 19-29 : 20

Key to the species of Commelina in the Andaman and Nicobar Islands

1. Spathes terminal, cucullate ........................................................................................................................................... 2

- Spathes leaf opposed, conduplicate .............................................................................................................................. 3

2. Plants erect to scrambling with a definite base; seeds ridged, 5 within a capsule ................................ C. benghalensis

- Plants trailing without a definite base; seeds smooth, 2 within a capsule .............................................. C. andamanica

3. Seeds smooth ................................................................................................................................................................ 4

- Seeds reticulate ............................................................................................................................................................. 6

4. Spathes hastate at base; seeds appendaged at both ends ............................................................................. C. attenuata

- Spathes cordate at base; seeds not appendaged ........................................................................................................... 5

5. Spathes ciliate at base; upper cincinnus ca. 0.5 cm long ........................................................................ C. caroliniana

- Spathes not ciliate at base; upper cincinnus ca. 1 cm long ........................................................................ C. longifolia

6. Leaves glabrous adaxially; spathe glabrous; seeds 5 within a capsule, doubly reticulate .............................. C. diffusa

- Leaves scabrous adaxially; spathe often pilose; seeds 4 within a capsule, shallow-reticulate ....................... C. clavata

1. Commelina andamanica S.M. Joseph & Nampy , sp. nov., Fig. 1 ; Plate 1 ; Plate 2A 1–E1

Figures

FIGURE 1. Commelina andamanica S.M. Joseph & Nampy. A. Flowering twig; B. Spathe; C. Lateral sepals; D. Medial sepal; E. Clawed petal; F. Medial petal; G. Staminode; H. Lateral stamen; I. Medial stamen; J. Gynoecium; K. Capsule; L. Seed-dorsal view; M. Seed-ventral view (drawn by Manudev from Santhosh Nampy & Manudev 3131).

PLATE 1. Commelina andamanica S.M. Joseph & Nampy. A. Habit; B. Cincinnus; C. Spathe; D. Sheath apex showing white hairs; E. Flower; F. Calyx and Corolla; G. Sepals; H. Lateral stamen; I. Medial stamen; J. Staminode; K. Gynoecium; L. Seeds-ventral & dorsal views (all from Sheba M. Joseph & Santhosh Nampy 4560).

PLATE 2. Comparison of Commelina andamanica S.M. Joseph & Nampy (A1-E1), C. ensifolia R. Br. (A2–E2) and C. suffruticosa Blume (A3–E3). A1–A3. Flowering twig; B1–B3. Clawed petal; C1–C3. Antherode; D1–D3. Capsule; E1–E3. Seeds. (A1–E1 from Sheba M. Joseph & Santhosh Nampy 4560; A2–E2 from Manudev 4076; A3–E3 from Manudev & Sheba M. Joseph 4561).