Xyris, L.

Rakotonirina, Nivo, Callmander, Martin W., Phillipson, Peter B. & Lock, J. Michael, 2014, Two new species of Xyris L. (Xyridaceae) endemic to Madagascar with a key to the Malagasy species, Candollea 69 (2), pp. 171-178 : 172-173

Key to the Malagasy species of Xyris

1 Keel of lateral sepals entire; bracts, leaf and stem bases pale or dark brown when dried ....................................... 2

1a. Keel of lateral sepals toothed, at least in the middle; bracts, leaf and stem bases always dark brown when dried ....... 5

2 Scape spirally twisted, base swollen, bulbous; leaves filiform, c. 1 mm wide............................................. X. labatii

2a. Scape straight, not twisted, base not swollen; leaves linear, more than 2 mm wide .......................................... 3

3. Bracts with a distinct sub-terminal, triangular or rhomboid mark; inflorescence broadly ovoid at anthesis, or rarely subspherical; plants perennial ........................................ 4

3a. Bracts without a distinct sub-terminal, triangular or rhomboid mark; inflorescence sub-spherical at anthesis; plants usually annual ................................................ X. capensis

4. Keel of lateral sepals not winged; bract apices conspicuously thickened, dark brown, somewhat recurved; plant less than 15 cm tall .......................................... X. humilis

4a. Keel of lateral sepals winged; bract apices not conspicuously thickened, light brown, not recurved; plant more than 25 cm tall .......................................................... X. anceps

5. Leaves large (0.6-0.8 cm); inflorescence c. 10 mm in diam., broadly ovate-elliptic, not elongating with age ................. ؆؆؆؆؆؆؆؆؆؆؆؆؆؆؆؆؆؆؆؆؆؆؆؆؆؆؆؆؆؆؆. X. marojejyensis

5a. Leaves narrow (<0.3 cm); inflorescence <6 mm in diam., sub-orbicular or ovate, becoming distinctly elongated with age................................................................................... 6

6. Leaves 40-75 × 0.3 cm; inflorescence ovoid-cylindrical, c. 2 cm long at anthesis .................................... X. baronii

6a. Leaves 20-40 × 0.15-0.2 cm; inflorescence ellipsoid, c. 1 cm long at anthesis................................ X. congensis