Two new species of Tynanthus Miers (Bignonieae, Bignoniaceae) from Brazil

Abstract Tynanthus is a genus of lianas that is broadly distributed through the Neotropics. Two new species of Tynanthus from Brazil are here described and illustrated: Tynanthus densiflorus, from Amazonas, and Tynanthus espiritosantensis, from Espírito Santo. Tynanthus densiflorus is recognized by the conspicuous interpetiolar glandular fields, a feature rarely found in Tynanthus, and the dense thyrses. Tynanthus espiritosantensis, on the other hand, is recognized by the bromeliad-like prophylls of the axillary buds and the lax thyrses. Information on the distribution, conservation status and morphologically similar species are provided.


Introduction
Tynanthus Miers (Bignonieae, Bignoniaceae) is a monophyletic genus of lianas that is easily recognized by small bilabiate fl owers, fruits with raised margins and by the smell of cloves in vegetative organs (Lohmann 2006). Th ese features, along with fl owers arranged in thyrses, corolla externally densely pubescent, thecae curved forward, ovary densely pubescent and poorly developed nectar disk characterize the genus (Medeiros and Lohmann submitted). Species of Tynanthus are distributed throughout the Neotropics, occurring predominantly in wet forests (Lohmann and Taylor 2014). Th e highest diversity of Tynanthus is found in Brazil, with most species occurring in Amazonia and the Atlantic Forest.
During the preparation of a taxonomic revision of Tynanthus (Medeiros and Lohmann submitted), multiple collections with morphological features that did not match any of the described species were found. Additional fi eldwork and molecular phylogenetic studies provided further support for the recognition of two new species in the genus, one from the Amazon region and another from the Atlantic Forest of Brazil.
Distribution and habitat. Known from wet forests in Manaus and proximity (Amazonas, Brazil).
Etymology. Th e species epithet refers to the thyrses with fl owers densely arranged. Phenology. Flowers in August. Fruiting period is unknown. Conservation status. According to IUCN (2001) criteria, this species is considered Vulnerable (VU B2ab(iii)). Th e type collection is from a protected area (Reserva Florestal Adolpho Ducke), where a reasonable number of individuals are found (pers. obs.). Nevertheless, the proximity of Manaus can be considered a region characterized by continuous urbanization. Additional studies on distribution and abundance of T. densifl orus are still necessary in order to confi rm its conservation status.
Discussion. Tynanthus densifl orus is characterized by dense thyrses, with a corymbose to conical aspect, as well as the presence of interpetiolar glands. Th e type collection of T. densifl orus was treated as T. panurensis (Bureau) Sandwith for the Guide of the Ducke Reserve (Lohmann and Hopkins 1999). Indeed, the two species are similar in the occurrence of ovate leafl ets and corolla tube that is internally tomentose at base. However, the presence of interpetiolar glands in T. densifl orus (versus absent in T. panurensis), the minute prophylls (versus foliaceous in T. panurensis) and dense infl orescences (versus lax in T. panurensis) allow the distinction of these taxa. Tynanthus pubescens A.H. Gentry is another species that is morphologically similar to T. densifl orus. Both taxa have similar corolla lengths (around 1-1.6 cm in T. pubescens) and show interpetiolar gland fi elds; however, the caudate-mucronate leafl et apex (versus acuminate or obtuse-mucronate in T. pubescens) and the dense infl orescences (versus lax in T. pubescens) diff erentiate both taxa. , lack of patelliform trichomes on petioles, petiolules and infl orescence axis (versus presence in T. schumannianus) and larger calyx, 2.3-2.7 mm long, 1.8-2.5 mm wide (versus 1-2 mm long, 1.1-1.9 mm wide in T. schumannianus).
Distribution and habitat. Known exclusively from wet forests in Linhares and proximity (Espírito Santo, Brazil).
Etymology. Th e species epithet refers to the type locality. Phenology. Flowers from December to February. Fruiting period is unknown. Conservation status. According to the IUCN (2001) criteria, this species is considered Data Defi cient (DD), given the small number of known collections. Further detailed investigation on the distribution of T. espiritosantensis is necessary in order to properly assess its conservation status. Th e two localities in which this species has been collected fall within a single municipality (Linhares), suggesting that this might represent another narrowly distributed species of Tynanthus. Fortunately, the type collection was obtained inside a protected area (Reserva Natural da CVRD).
Discussion. Tynanthus espiritosantensis is characterized by the bromeliad-like prophylls of the axillary buds and lax thyrses. Th is species is morphologically similar to the Amazonian T. schumannianus (Kuntze) A.H. Gentry. However, these taxa can be easily separated by the pubescent leafl et domatia (versus glabrous in T. schumannianus), absence of patelliform glands on petioles, petiolules and infl orescence axis (versus presence in T. schumannianus) and the larger calyx, 2.3-2.7 mm long, 1.8-2.5 mm wide (versus 1-2 mm long, 1.1-1.9 mm wide in T. schumannianus). Additional