Key to the species of Jaltomata of Mexico (based on Mione & Spooner 2010)

1a. Anthers unequal in size, most noticeable during the pistillate phase while anthers are undehisced; filaments sigmoid or curved during hermaphroditic phase; style curved; habitat in coffee plantations and roadsides ......................................... J. repandidentata

1b. Anthers equal in size; filaments straight during hermaphroditic phase; style straight; habitat variable, including agricultural fields and other disturbed areas ....................................................................................................................................................................2

2a. Calyx lobes concave in cross section; calyx purple at time of flowering, ˂ 6.8 mm diam ............................................... J. bohsiana

2b. Calyx lobes plane to reflexed in cross section; calyx mostly green at time of flowering, ˃ 7 mm diam............................................3

3a. Anthers longer than 2.8 mm; leaves and branches densely velutinous ......................................................................... J. grandiflora

3b. Anthers shorter than 2.8 mm; leaves and branches glabrate to pubescent or hirsute.........................................................................4

4a. Vestiture of stems and leaves variable (including glabrate) but never hirsute; habit erect; corolla 5-lobed or with alternating lobes and lobules totaling 10; flowers per inflorescence up to 18 flowers; colour of fruit black or dark purple when ripe; Arizona, United States, to Ecuador ......................................................................................................................................................... J. procumbens

4b. Vestiture of stems and leaves glabrate to hirsute; habit prostrate or decumbent; colour of fruit black or green when ripe; corolla 5-lobed; flowers per inflorescence less than 5 ...................................................................................................................................5

5a. Stems and leaves hirsute; habit prostrate; corolla pale green, 5 attenuate lobes; inflorescence up to 4-flowered; obtuse or obtuseacuminatecalyx; plants with fruit colour purple or green when ripe; northern Mexico ............................................ J. chihuahuensis

5b. Leaves glabrate and vestiture of stems variable (including glabrate) but never hirsute; habit prostrate or decumbent; corolla pale yellow, and dark green flower base with a ring appearance, 5 pyramidal lobes; inflorescence up to 3-flowered; pyramidal-shaped calyx; pale green fruit with few dark green or purple vertical lines when ripe, with a slight purple spot on one side of the fruit; associated with agricultural fields; Central Highland Valley of Mexico ............................................................................. J. tlaxcala