Pogonopus

• Authority

  Delprete, Piero G. 1999. Rondeletieae (Rubiaceae). Part I. Fl. Neotrop. Monogr. 77: 1-226. (Published by NYBG Press)

• Family

  Rubiaceae

• Scientific Name

  Pogonopus

• Type

  Type species. Pogonopus ottonis Klotzsch [= P. speciosus (Jacquin) K. Schumann var. speciosus].

• Synonyms

  Carmenocania, Chrysoxylon, Howardia, Pogonopus ottonis Klotzsch, Pogonopus speciosus var. speciosus, Carmenocania porphyrantha Wernham, Pogonopus speciosus var. speciosus, Chrysoxylon febrifugum Wedd., Pogonopus tubulosus (A.Rich. ex DC.) K.Schum., Howardia febrifuga Wedd., Pogonopus tubulosus (A.Rich. ex DC.) K.Schum.

• Description

  Genus Description - Shrubs, rarely treelets, much-branched; outer branches often scandent, main trunk (when present) short. Stipules interpetiolar, free at base, sometimes adnate to the petioles, small, deltoid to shallowly triangular, persistent; stipules in apical buds with axillary colleters that secrete a sticky yellow resin. Leaves petiolate, elliptic to obovate, foliaceous; petioles short, thickened at base; domatia absent, or tuft domatia with sparse hairs (rarely pocket domatia). Inflorescences terminal, frondose, pyramidal, laxly paniculate, each lateral branch subtended by leaf-like bracts, terminating in a small cyme. Flowers protandrous; hypanthium obconical to obovoid (rarely turbinate). Calyx extremely reduced, caducous; lobes 5; 1-5 calyx lobes expanded into colorful calycophylls in some flowers. Calycophylls shortly stalked and blades ovate to obcordate to reniform. Corolla tubular with short lobes, membranaceous or fleshy when fresh; tube cylindrical, basally constricted, with a ring of hairs at base inside; lobes 5, erect to spreading, triangular to ovate; aestivation valvate-reduplicate with contact zones. Stamens 5, exserted well above the corolla, attached near the base of the corolla tube (just above the constriction); filaments thin, with a tuft of hairs at base; anthers elliptic-oblong, dorsifixed at medial zone, dehiscing by longitudinal slit. Pollen tricolporate, exine reticulate. Style exserted well above the corolla; style branches linear to oblong. Ovary 2-celled, turbinate, glabrous, placentation axile; ovules many in each locule, horizontally inserted; immature fruits green and semi-carnose when fresh. Capsules obovoid, oblong to globose, truncate at apex, often with white lenticels; dehiscing loculicidally, disk septicidal dehiscence present in old capsules. Seeds many, horizontal, irregularly shaped, 3-5-angled, compressed.

• Discussion

  Pogonopus is commonly encountered as beautiful multi-stemmed shrubs (rarely single-stemmed trees), with highly ornamental red-purple calycophylls. It is easily recognizable because of its long-tubular pink-red flowers, small deltoid stipules with a tuft of hairs between them, and small capsules with horizontally inserted seeds. Its seeds are minute, non-winged, truncate at the apex, and posses a reticulate and minutely tuberculate exotesta (within the primary reticulation). Its bark is often reported to be a good remedy for malaria and intermittent fevers, and more recently for its antitumor properties (for additional information see under Uses).

  Pogonopus (see Figs. 53, 55, 56, 57) is closely related to Pinckneya, from southeastern North America. The latter differs from the former in having corolla cream-white, its throat without a ring of hairs (present in Pogonopus), corolla lobes long-narrow pubescent inside, and coiling outward at anthesis (vs. spreading), seeds arranged in two vertical ranks, with orbicular wing (vs. many minute unwinged seeds), and exotesta secondarily reticulate (within the main reticulation).
  The distribution of Pogonopus is an interesting case of geographical vicariance (see Fig. 54). Restricted to tropical seasonal forests, this genus occurs in two areas of distribution that mirror to each other with respect to the equator. In the northern hemisphere Pogonopus ranges from Chiapas (southern Mexico) to northern Colombia, from 6°N to 16°N; while in the southern hemisphere it occurs from central Peru to northern Argentina, from 9°S to 22°S. Pogonopus also occurs along elevational gradients and is usually encountered at medium elevations of (50-)500-1400 m. I attribute the occurrence of Pogonopus in the lowlands to its introduction into cultivation for its ornamental and medicinal properties. Pogonopus is here treated as a genus of three species and two varieties.
  Taxonomic History
  Pogonopus was established by Klotzsch in 1853; its name was derived from the Greek words [Greek symbols] [pogon = beard] and [Greek symbols] [pous = feet], because of its basally bearded filaments. The first species described under this genus was P. ottonis [= P. speciosus (Jacq.) K. Schum. var. speciosus], from material collected in Venezuela, with the specific name dedicated to its collector [Otto 901]. Klotzsch (1853) also noted that another species (from Costa Rica) should be included in Pogonopus, namely Macrocnemum exsertum Örsted (Örsted, 1852), but he did not make the official transfer. When Klotzsch (1853) described P. ottonis, he was perhaps unaware that this species was already described by Jacquin (1797) as Macrocnemum speciosus. The latter was transferred to Pogonopus much later by Schumann (1889).
  Augustin Pyramus de Candolle (1830) transferred Macrocnemum tubulosum A. Rich, in DC. [= Pogonopus tubulosus (A. Rich, in DC.) K. Schumann] to Calycophyllum, which in turn was placed next to Pinckneya [as "Pinkneya"], within his Cinchoneae.
  Weddell (1849) described Chrysoxylon, an invalid name because this generic epithet was previously used by Casaretto (1843) for a mimosoid genus. Realizing the invalidity of his Chrysoxylon, Weddell renamed this genus Howardia, ignoring (purposely or otherwise) the fact that Klotzsch (1853) had meanwhile described it as Pogonopus (the valid name for this genus). Under Howardia, Weddell (1854) described four species: H. caracasensis and H. grandiflora, both using Venezuelan collections (and both = P. speciosus var. speciosus); and H. richardi (based on Macrocnemum tubulosum A. Rich.) and H. febrifuga (based on Chrysoxylon febrifugum), both using Bolivian collections (and both = P. tubulosus). Weddell (1854) also commented that Calycophyllum tubulosum (A. Rich, in DC.) DC. shared many affinities with his Howardia and, instead of making a new combination, he reduced this species under synonymy of his H. richardi.
  Hooker (1873) established the tribe Condamineeae, and in his third subtribe Pinckneyinae he placed Pogonopus and Pinckneya.
  Baillon (1880) included Pogonopus under Pinckneya, simply stating (translated from French): “In those named Pogonopus, the corolla, instead of being tomentose internally, is glabrous. The fruit is ovoid, whilst in the true Pinckneya [as Eupinckneya] it is more globular and subdidymous. They are shrubs of the two Americas, with rather large and showy flowers in terminal or axillary clusters of cymes." Wemham (1912) described Carmenocania, a genus that he included in the Mussaendeae. The type collection, Schlim 755, is from the vicinity of the city of Carmen, in the province of Ocaña (hence the generic name), Venezuela [and not Colombia as reported by Wemham (1912), Standley (1930a), and Sandwith (1949)]. Wemham apparently overlooked that this was the same collection previously used by Weddell (1854) to establish Howardia grandiflora.
  Standley (1918) reduced Chrysoxylon and Howardia to synonymy under Pogonopus, but subsequently he (Standley, 1930a) listed Pogonopus (in the Condamineeae) and Carmenocania (in the Mussaendeae) without noting their similarities. Sandwith (1949) recognized the mistakes made both by Wemham (1912) and Standley (1930a) and synonymized Carmenocania under Pogonopus.
  Steyermark (1971) divided Pogonopus speciosus into three subspecies: exsertus, speciosus, and sandwithiana. He later reduced subsp, sandwithianus to a variety under P. speciosus subsp, speciosus (Steyermark, 1974). In the present treatment P. exsertus is returned to specific rank (Orsted, 1863) and the subspecific divisions are no longer maintained. As here treated, Pogonopus consists of three species, one with two varieties, collectively ranging from southern Mexico to northern Argentina.