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Revision of Spathacanthus
Spathacanthus hoffmannii

Thomas F. Daniel
Department of Botany
California Academy of Sciences
Golden Gate Park
San Francisco, CA 94118

Main

Characteristics

Phylogenetic Analysis

Generic Description & Key to Species

S. hahnianus

Additional Specimens Examined

S. hoffmannii

Additional Specimens Examined

S. parviflorus

Additional Specimens Examined

Acknowledgments & Literature Cited



Figure Legend:

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

 

Spathacanthus hoffmannii Lindau, Bull. Herb. Boissier 3: 370.  1895.---TYPE: COSTA RICA.  Alajuela: prope Aguacate, Aug 1857, C. Hoffmann 842 (holotype: B, destroyed, photos: F!, GH!, US!).

 Shrubs to small trees to 8 m tall, trunk (often with multiple trunks) up to 10 cm in diameter.  Young stems quadrate to somewhat flattened, glabrous (or the nodes pubescent with brownish, flexuose eglandular trichomes).  Leaves subsessile to petiolate, petioles to 15 mm long, blades elliptic to elliptic-obovate to obovate, 89--285 mm long, 25--109 mm wide, 1.8--5.2 times longer than wide, abruptly acuminate to apiculate at apex, acute to attenuate at base, surfaces and margin glabrous.  Inflorescence a terminal raceme to 35 mm long (excluding flowers), rachis pubescent like young stems; dichasia 1-flowered, sessile.  Bracts triangular to lanceolate, 2--8 mm long, 1--1.3 mm wide, abaxial surface glabrous.  Bracteoles lance-subulate, 2--5 mm long, 1--1.5 mm wide, abaxial surface glabrous.  Flowers pedicellate, pedicels to 9 mm long, 3.1 mm in diameter in fruit, glabrous.  Calyx green, 25--40 mm long (somewhat accrescent in fruit), (8--) 10--16 mm in diameter (measured flat), abaxially glabrous, beaked in bud with a beak 0.6--1.2 mm long, equally or subequally divided into 2 ovate to elliptic to obovate-elliptic segments, incisions 11--22 (--28) mm long (rupturing further when capsules dehisce), 0.34--0.73 times as long as calyx, 1 segment apically entire, other segment apically entire or 2-lobed, lobes triangular, to 1.5 (--5) mm long.  Corolla white, 73--97 mm long, narrow proximal portion of tube 18--30 mm long, 2--5 mm in, internally pubescent, throat 35--50 mm long, 9--18 mm in diameter near midpoint, limb 30--42 mm in diameter, upper lip 15--26 mm long, lobes ovate to elliptic, 10--20 mm long, 11--18 mm wide, lower lip 18--25 mm long, lobes ovate to elliptic, 15--20 mm long, 12--16 mm wide.  Stamens with longer pair 24--34 mm long and shorter pair 18--28 mm long, thecae 4--6 mm long; pollen subprolate to euprolate, 3-colporate, polar diameter 65--71 µm, equatorial diameter 44--56 µm, P:E = 1.16--1.62, exine foveolate to foveolate-verrucate to subrugulate.  Style 44--59 mm long, stigma lobes 0.3--0.6 mm long.  Capsule 50--89 mm long, stipe 20--40 mm long, head 27--39 mm long, retinacula 7--12 mm long.  Seeds somewhat irregularly shaped to subcordate to subelliptic in outline, 7.5--13 mm long, 7.5--11 mm wide, 3--5 mm thick, surface with shallow subconcentric ridges (especially toward margin).
 
Illustration.  Fieldiana, Bot. (n.s.) 18: 19, fig. 17, 1986.

Phenology.  Flowering: January--March and May--October; fruiting: December--March, and May--September.

Distribution (Fig 5).  Costa Rica (Alajuela, Cartago, Guanacaste, Heredia, Limón, Puntarenas, and San José); along streams in regions of humid forests, rain forests, and cloud forests on both the Caribbean and Pacific escarpments; 80--1700 m.

Based on the cladistic analysis Spathacanthus hoffmannii is more closely related to S. hahnianus than to S. parviflorus.  The former two species both have long corollas with the lower lip terminating in relatively long lobes.  Like S. parviflorus however, S. hoffmannii has white corollas..

[Additional Specimens Examined]