Apomuria

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 : 58-60

Apomuria

Bremekamp’s Apomuria

BREMEKAMP (1963) also separated Apomuria from Psychotria by pyrene form plus the pattern of endosperm rumination, and his circumscription and characterization of this genus were also problematic morphologically. He diagnosed this genus by pyrenes that are generally plane (i.e., not grooved) adaxially, and endosperm that is entire (i.e., not ruminate) except for a distinctively shaped, medial, adaxial groove or invagination ( Fig. 4B, D ). This hollow adaxial groove intrudes deeply into the endosperm, then branches to form two flattened, hollow “wings” or extrusions that extend laterally; he called this a T-shaped intrusion. Bremekamp included in Apomuria 11 species from Madagascar, and A. punctata (Vatke) Bremek. of the Comores and East Africa. This group is heterogeneous morphologically overall, and some of these species have morphological features that he did not include in the characterization of the genus (e.g., endosperm with several unbranched ruminations in addition to the characteristic T-shaped intrusion, Fig. 4B, D ) while others have characters he did not notice. BREMEKAMP (1963: 88) also mentioned that some additional species in continental Africa shared the characters of Apomuria , and he stated that they also belong to Apomuria but did not provide a complete list of these or nomenclatural transfers. One of these was Psychotria kirkii Hiern , which lacks a T-shaped intrusion in the endosperm but has multiple adaxial ruminations ( Fig. 4E ). The continental African species, including Apomuria punctata , all have bacterial nodules in their leaves, which is an unusual feature in Psychotria . Bremekamp noted this character but did not consider it significant to diagnose a genus. He included his Malagasy species with bacterial nodules in Psychotria , not Apomuria , and considered the Malagasy species of Apomuria to all lack nodules. But, he overlooked the nodules of A. bullata Bremek. (newly reported here: Perrier de la Bâthie 6926, P image seen; Dorr 3237, MO). Thus, Bremekamp’s circumscription and characterization of Apomuria are based on both variable characters and incomplete documentation of the species.

PETIT (1964, 1966) evaluated these particular pyrene and endosperm characters and concluded that they are highly variable. He documented several African Psychotria species with Apomuria ’s characteristic endosperm ruminations that differ in all their other features from all of Bremekamp’s species, and concluded ( PETIT, 1964: 24) that Apomuria was not separable from Psychotria . PIESSCHAERT (2001: 317) also evaluated these pyrene and endosperm characters, and showed that endosperm rumination is highly variable in Psychotria . Piesschaert studied limited material from Madagascar, but CAPURON (1973) reached a similar conclusion for the Malagasy Psychotria . Apomuria was included in Psychotria by SCHATZ (2001), but continued to be recognized in Madagascar by other authors (e.g., DAVIS et al., 2007).

Bremekamp’s Apomuria analyzed with molecular data ANDERSSON (2002) showed that the T-shaped endosperm intrusion is highly homoplasious in world-wide Psychotria , and concluded that Apomuria is not separable morphologically based on this diagnostic feature and formally synonymized it

[A: Du Puy et al. 757; B: Villiers 4881; C–D: Barthelet et al. 1474; E: Kuchar 23683; F–G: Blackburn 3200; H–I: Andriananrista 126;

J: Antilahimena 2657; K–N: Bollinger et al. 240; O–P: Antilahimena 403]

with Psychotria . RAZAFIMANDIMBISON et al. (2014) studied two species of Apomuria , both of which are nodulated species and neither of which is the type. They found these species separated from each other and grouped with species of Psychotria , and agreed with its synonymization.

Figures

Fig. 4. – Some morphological features of Psychotria L. in Madagascar. A–B. Apomuria, Psychotria biloba (Bremek.) A.P. Davis & Govaerts: A. Fruiting branch; B. Cross-section of seed (removed from pyrene). C–D. Apomuria, Psychotria punctata Vatke: C. Fruit; D. Cross-section of seed. E. Psychotria kirkii Hiern, cross-section of seed. F–G. Psathura, Psychotria borbonica (J.F. Gmel.) Razafim. & B. Bremer: F. Fruit; G. Cross-section of fruit, with four pyrenes. H–I. Psathura, Psychotria batopedina (Verdc.) Razafim. & B. Bremer: H. Fruit; I. Cross-section of fruit, with five pyrenes. J. Unusual stipules in Malagasy Psychotria L. (TAYLOR, in press). K–N. Trigonopyren, Psychotria tsiandroi Razafim. & B. Bremer.: K. Node near stem apex with developed stipule, unbroken and with glandular projections; L. Node below the node shown in K, with aging stipule that is falling off in fragments; M. Node in lower part of stem, with old stipule that has fallen off except for persistent basal part of sheath; N. Cross-section of pyrene. O–P. Trigonopyren, Psychotria bealanensis Razafim. & B. Bremer: O. Fruit; P. Cross-section of fruit, with two pyrenes.