Psychotria (CAPURON, 1973)

Taylor, Charlotte M., 2020, Overview of Psychotria in Madagascar (Rubiaceae, Psychotrieae), and of Bremekamp’s foundational study of this group, Candollea 75 (1), pp. 51-70 : 67

Key to Psychotria and genera of Palicoureeae in Madagascar

The following key separates Malagasy genera that have commonly been confused with Psychotria . Because of the particular characters used to contrast genera in this identification key and the morphological variation in Psychotria , various groups of species of Psychotria are keyed in different leads.

1. Inflorescences regularly axillary (i.e., produced in both axils of nodes along the stem), short, subcapitate to congested-cymose ............................................................. 2

1a. Inflorescences terminal, pseudoaxillary (i.e., produced in one axil of a node along stem), or borne on short axillary shoots, variously subcapitate to congested-cymose, laxly cymose, or paniculiform .............................................. 3

2. Drupe when fully developed with two pyrenes that are each 1-celled; endosperm starchy .................. Psychotria

2a. Drupe when fully developed with 1 pyrene that is 1-celled; endosperm oily .................................................. Saldinia

3. Stipules generally deciduous via fragmentation with the persistent parts becoming hardened (i.e., indurated) and often yellowed, the sheath enclosing pubescence along the stem that dries whitened to yellowed or is deciduous ....................................................................... Chassalia

3a. Stipules completely deciduous, or deciduous via fragmentation with the persistent parts papery to somewhat hardened and turning brown or reddish brown, the sheath enclosing persistent or deciduous, ferruginous, pilosulous pubescence that is matted, whitish to ferrugineous, pilosehirsute pubescence, or deciduous pilosulous pubescence4

4. Pyrenes abaxially three-angled, longitudinally 4–5-ridged, or rounded and smooth; stipules pesistent to deciduous; erect shrubs and small trees .......................... Psychotria

4a. Pyrenes abaxially rounded and smooth; stipules persistent; creeping herbs ............................................................. 5

5. Leaves elliptic, acute to truncate or rounded at base; endosperm entire to ruminated in various patterns ................ ...................................................................... Psychotria

5a. Leaves cordiform, basal lobes well developed; endosperm entire ........................................................................... 6

6. Fruits red, orange, or blue ............................... Geophila

6a. Fruits yellow ........................................................ Puffia