Anisotes mayottensis T. F. Daniel, 2014

Daniel, Thomas F., 2014, Taxonomy of nisotes Nees (Acanthaceae: Justicieae) in the Comoros Archipelago and a preliminary list of canthaceae in the Islands, Candollea 69 (1), pp. 45-54 : 51-54

Anisotes mayottensis T. F. Daniel , spec. nova ( Fig. 3 , 4 ).

Typus: MAYOTTE: Bénara, 600 m, 26.V.1997, fl., Pascal 936 (holo-: CAS!; iso-: K, P!).

Species calycis lobis majoribus ovatis et 3-5 mm longis X 1.5-2 mm latis, corolla purpureo-rubra et 24-32 mm longa, et polline 4-aperturato a congeneribus diversa.

Shrubs to 1 m tall. Older stems dark greenish, brown, or slightly pinkish; younger stems evenly and ± densely pubescent with retrorsely to antrorsely appressed eglandular trichomes to 0.5 mm long. Leaves petiolate, petioles to 52 mm long, blades membranaceous, ovate, 56-116 mm long, 23- 44 mm wide, 2.1-3.4 X longer than wide, rounded to subcuneate at base, acuminate at apex, venation ± prominent, secondary veins 4-7 per side, surfaces pubescent (trichomes mostly restricted to midvein) with appressed eglandular trichomes. Spikes axillary, alternate or opposite at leaf nodes, 1- 2 per axil, densely bracteate, pedunculate, peduncles 4-15 mm long, pubescent with antrorsely appressed eglandular trichomes, fertile portion of spike (excluding corollas) 10-24 mm long, rachis not visible, nearly glabrous or sparsely pubescent with erect to flexuose eglandular trichomes to 0.2 mm long. Bracts green and lighter (hyaline) toward margin and apex, imbricate, 4-ranked (2 adjacent ranks fertile; thus ± secund), coriaceous, (ovate-elliptic to) elliptic (to obovate-elliptic), 5.5- 7.5 mm long, 2.7-3.5 mm wide, acute-apiculate at apex, apiculum to 0.5 mm long, abaxial surface puberulent with erect to antrorse eglandular trichomes to 0.05 (-0.1) mm long, major veins conspicuous, 5, parallel to midvein, margin ciliate with erect to flexuose eglandular trichomes to 0.8 mm long, proximal pair of bracts sterile. Bracteoles linear-oblanceolate, 4- 5.7 mm long, 0.8-1.2 mm wide, abaxial surface pubescent like bracts (to nearly glabrous), 1-3-veined, margin ciliate like bracts. Calyx either 5-lobed with 1 lobe conspicuously reduced or equally 4-lobed, 6-9 mm long, tube 3-4 mm long, 4 lobes ovate, 3-5 mm long, equal in length, 1.5-2 mm wide, subacuminate at apex, abaxially puberulent with eglandular and subglandular trichomes <0.05 mm long, margin hyaline and ciliate, 5 th lobe (if present) linear to lanceolate, 2-3 mm long, 0.5-1 mm wide, otherwise like larger lobes. Corolla purplish red, 24-32 mm long, externally pubescent with subglandular and eglandular trichomes <0.05-0.2 mm long, tube subcylindric proximally, expanded distally, 6-13 mm long (0.25-0.46 X as long as corolla), 2.5-3 mm in diameter near midpoint, upper lip 14-24 mm long, entire at apex, lower lip recoiled, 15-24 mm long, lobes 3 mm long, 0.9-1 mm wide. Stamens inserted near apex of corolla tube, 17-18 mm long, not extending beyond upper lip of corolla, filaments glabrous distally, thecae subparallel, unequally inserted (overlapping by 1-1.5 mm), 2- 2.5 mm long (± equal in length), glabrous, distal theca with a basal appendage 0.1-0.2 mm long, proximal theca with a basal appendage 0.3-0.6 mm long. Pollen 4-colporate, 8-pseudocolpate (the 2 pseudocolpi in each mesocolpium often fused near poles to form pseudocolpal ellipses), euprolate to perprolate, polar diameter (P) 41-60 µm, equatorial diameter (E) 21-27 µm, P:E = 1.56-2.86, exine bireticulate. Style 24-32 mm long, not extending or extending beyond upper lip of corolla, glabrous distally, stigma inconspicuous, lobes (if present) not evident. Capsule and seeds not known.

Phenology. – Flowering: May-June.

Distribution and habitat. – Comoros Archipelago; known from two relatively recent collections from the crests of the southern highlands on the island of Mayotte ( Fig. 1 ), where it is endemic; plants occur in humid evergreen forest (with Olea capensis L., Labramia mayottensis Labat, M. Pignal & O. Pascal , Dicoryphe platyphylla Tul. , Strychnos mitis S. Moore , Syzygium sp. , Gastonia duplicata Baill., Grisollea myriantha Baill. , Nuxia pseudodentata Gilg , Ravensara areolata Kosterm. , Scolopia coriacea Tul. , Trophis montana (Leandri) C. C. Berg ) at elevations between 350 and 600 m.

Local name. – “Nanatsy be” (Shibushi; Barthelat & al. 386).

Discussion. – This species shows variation in the number of calyx lobes from five (4+1) to four. The presence of both forms on Barthelat & al. 386 suggests that the reduced fifth lobe is sometimes lost. Similar variation in the number and configuration of calyx lobes is known for Justicia , but apparently has not been reported in other species of Anisotes . It is noteworthy that A. comorensis and at least one Malagasy species ( A. venosus T. F. Daniel, Letsara & Martín-Bravo ; DANIEL & al., 2013) have a calyx with one lobe somewhat reduced in size relative to the others.

The four-aperturate pollen of this species ( Fig. 2 ) is unusual in the genus. It has been previously documented only for the tropical west African species, A. guineensis Lindau ( BADEN, 1981b).

Paratypi. – MAYOTTE: Grande Terre , Tsararano, Bénara, Crètes du Bénara, 10.V.2001, Barthelat & al. 386 (MO, P); Grande Terre, Tsararano, Réserve Forestière du Bénara, ch. de crête-sommet, 27.V.2001, Barthelat & al. 1188 (P); Mlima Choungi, 10.VI.1996, Pascal 563 (P).

Figures

Fig. 3. – Anisotes mayottensis T. F. Daniel. A. Habit; B. Leaf; C. Bract; D. Bracteole; E. Calyx; F. Distal portion of stamen with anther. [A, C-E: Barthelat & al. 386, MO; B, F: Pascal 936, CAS] [Drawing: Noel Pugh]

Fig. 4. – Anisotes mayottensis T. F. Daniel. Distal portion of stem with inflorescences. [Photo: F. Barthelat (used with permission)]

Fig. 1. – Comoros Archipelago (Union of the Comoros and Mayotte) showing distributions of Anisotes comorensis (Lindau) T. F. Daniel and A. mayottensis T. F. Daniel. The exact location of the sole collection of A. comorensis (Lindau) T. F. Daniel from Grande Comore is unknown.

Fig. 2. – Pollen of Anisotes Nees in the Comoros Archipelago. A-B. Anisotes mayottensis T. F. Daniel; C-D. A. comorensis (Lindau) T. F. Daniel; A. Apertural view; B. Interapertural view; C. pertural view; D. Interapertural view. [A-B: Pascal 936, CS; C-D: Humblot 1584, P]