Two new species for Gochnatia Kunth (Asteraceae, Gochnatieae) and an extension of the tribal range into Ecuador

Abstract Two new species are added to the narrowly delimited genus Gochnatia. Of these, G.lojaensissp. nov. represents a northern extension of the genus and tribe into Ecuador and G.recticulifoliasp. nov. occurs in northern Peru. In addition to descriptions for the two new species, a key is provided for all known species in the genus Gochnatia and a pubescence character is noted that clearly separates Gochnatia from Moquiniastrum.


Introduction
In the process of working on the treatment of the tribe Vernonieae (Asteraceae) for the Flora of Ecuador (Robinson and Funk 2018), an unidentified specimen that came in on loan from AAU was determined not to be Vernonieae. Although it seemed to belong to the tribe Gochnatieae J. Panero & V.A.Funk, that tribe had not been reported from Ecuador (Funk et al. 2014). In trying to identify the specimen, other Gochnatieae from US were examined and two more specimens were found that were questionable as to species. The first of these three specimens remained in a folder of "work to be done" for a number of years. As the loans were being annotated in preparation for their return, the folder reappeared. One of the three specimens was determined to be a slight variant of Gochnatia arequipensis Sandwith. The remaining two specimens were more difficult to assign to a known species and eventually we decided they were new to science. The two species can now be described as true members of narrowly defined Gochnatia Kunth, a genus that is primarily of Central Andean distribution.
The genus Gochnatia was revised by Cabrera (1971) and subsequently it became the basis for a tribe Funk 2002, 2007;Sancho and Freire 2009). The recent history of the basal tribes was summarized by Ortiz et al. (2009). Recent papers on the immediate group of genera include Katinas et al. (2008) and Funk et al. (2009Funk et al. ( , 2014. Generic level papers include those on Richterago Kuntze (Roque and Pirani 2001), Anastraphia D.Don (Ventosa-Rodríguez and Herrera-Oliver 2011), Moquiniastrum (Cabrera) G.Sancho (Sancho et al. 2013), and Nahuatlea V.A.Funk (Funk et al. 2017). These efforts have further refined our concepts. Some species that Cabrera included in the genus Gochnatia (s.l.) such as the Asian taxa are reinstated in their own genera (Leucomeris D.Don and Nouelia Franch.) and have been placed in a different tribe (Hyalideae) and are therefore, not part of the Gochnatieae. Others, like Cnicothamnus Griseb. and Cyclolepis Gillies ex D.Don had not been placed in Gochnatia s.l. by Cabrera (1971) and are now associated with the tribe. There are now 7 genera and 57 species in the tribe and Gochnatia s.s. now contains 10 species. In contrast, the tribe Hyalideae Panero, typified by the genus Hyalis D.Don ex Hook. & Arn., was placed in subfamily Wunderlichioideae and contained four genera: Ianthopappus Roque & D.J.N.Hind, Hyalis D.Don ex Hook & Arn., Leucomeris, and Nouelia, and a total of six species. Recent results from next generation sequencing (Mandel et al. 2019) demonstrated that the Hyalideae are now better placed in the Stifftioideae.

Methods
Collections were studied from the following herbaria: AAU and US. Morphological characters were assessed and measured from herbarium material. Florets and fruit were rehydrated in water prior to dissection and measurement. Other characters were measured directly from the herbarium specimens. Some parts such as trichomes were mounted on slides in Hoyer's solution (Anderson 1954). Corolla color, habit and habitat information were taken from the labels of the holotypes. Both species are only known from the type collection.
Distribution and ecology. Known only from the type collection which places it in "Matorral vegetation and ravine with disturbed remnants of montane forest." Conservation status. DD (according IUCN 2019).   Etymology. Gochnatia lojaensis is named after the Ecuadorian province where it was collected.
Notes. Distinguishing characteristics include the corymbiform clusters of numerous heads and the narrow castaneous involucral bracts with narrowly blunted tips.
The position of the new species was at first in doubt. It was near the geographic range of Gochnatia typified by G. vernonioides Kunth from Peru, but it had the more elongate leaves often associated with the presently recognized separate genus Moquiniastrum. A detailed study of the plant now confirms a position in Gochnatia: the pubescence is particularly indicative, being a thick tomentum and not the loose stalked T-shaped hairs common in Moquiniastrum (Fig. 5F). The hairs do show one interesting tendency toward the T-shaped form, with some hairs having an apical cell that is obliquely mounted on the longer contorted cell. Such an apical cell usually has the lower end slightly projecting, a sub-T-shaped specialization. This remains totally different from the well-developed T-shape form seen in Moquiniastrum (Fig. 5F). Description. Shrub to 3 m tall; stems gnarled, thickened and blackish near base, to ca. 8 mm wide, with scarcely noticeable narrow pith; younger stems as slender shoots, with internodes 3-10 mm long, covered with grayish tomentum. Leaves alternate, petioles ca. 4 mm long; laminae ovate oblong, mostly 1.6-2.5 cm long, 1.2-1.8 wide, flat or sometimes folded along midvein, base short-obtuse, apex usually rounded with slight mucro, margins flat, not recurved, entire, adaxial surface greenish with minute thin evanescent floccose puberulence, abaxial surface with grayish granular-looking pubescence consisting of slender highly contorted trichomes with few thin-walled cells at base, sometimes with slightly off-set apical cells separated by an oblique cross-wall, with a weakly prominulous midvein, 3 or 4 pairs of ascending, secondary veins, and a minute reticulum of veinlets evident on both surfaces that are not obscured by pubescence. Inflorescence of a solitary capitulum or 2-3 grouped together at tips of leafy stems; involucres broadly campanulate at anthesis, ca. 9 mm high and 11 mm diam., bracts ca. 40 in ca. 6 gradate series, basal bracts broadly ovate, 1.5-2.5 mm long, to 2.5 mm wide, rounded to obtuse at tips, inner bracts lanceolate, to ca. 7 mm long, acute, outer surface thinly pilosulous with weak indumentum near bases; receptacle slightly crested between areoles. Florets homogamous 35-40 per capitulum, corollas yellow, ca. 8-9 mm long, without long hairs outside, basal tube ca. 3.5 mm long, throat ca. 1.5 mm long, narrowly funnelform, lobes linear, ca. 3.5 mm long, ca. 0.2 mm wide; anther thecae ca. 1.8 mm long, tails ca. l.2 mm long, with a dense fringe of narrow hairs, apical appendage ca. 0.9 mm long, narrowly ovate with acuminate tip; pollen 30-40 µm in diam. and 50-55 µm long; styles slightly broadened and blunt at tips. Achene cylindrical, ca. 4 mm long, sericeous with slender setulae; pappus pale yellow with ca. 35 inner capillary bristles, up to 7 mm long, most with distinctly broader and more densely scabrous tips, and with numerous outer shorter weakly barbellate bristles of various lengths with slender tips.

Gochnatia recticulifolia
Distribution. Known only from the type collection which places it in northern Peru. Conservation status. DD (according IUCN 2019). Etymology. The epithet for Gochnatia recticulifolia is based on the minute reticulum of veinlets that is evident on both surfaces of the leaf.
Notes. The type specimen was original identified in the herbarium as G. curvifolia S.F.Blake, a potentially related species of mostly Bolivian distribution. However, G. curvifolia has pointed leaf tips and a minute reticulum of the leaf veins mostly obscured by pubescence. The corollas of G. recticulifolia have no hint of the pilosity seen in many but not all specimens of G. curvifolia and the closely related G. boliviana S.F. Blake. G. recticulifolia may actually be closer to the unseen G. vargasii Cabrera of the Department of Apurimac in Peru, but the latter is distinct in having more acute leaves and serrate leaf margins.
As a result of our investigations we emphasize the trichome character that provides an additional distinction between Gochnatia s.s. and Moquiniastrum: the trichomes on the abaxial surface of the leaf. In Gochnatia they are slender, highly contorted trichomes with a few thin-walled cells at base, sometimes with slightly off-set apical cells separated by an oblique cross-wall ( Fig. 5C-E). In Moquiniastrum the trichomes are T-shaped, often long-stalked with an elongate cap-cell attached at the mid-point (Fig. 5F). We examined the generitypes of both genera as well as our two new species. Gochnatia vernonioides (Fig. 5E), the generitype of Gochnatia has some trichomes with two such oblique cross-walls and off-set cells. Certainly, the distribution of this character should be examined for all 10 species in an upcoming monograph of Gochnatia s.s. (Sancho et al., in prep.).
The 10 species now recognized in Gochnatia can be distinguished by the following key. Many details are from Cabrera (1971), especially regarding G. vargasii of which proper material has not been seen. Excluded is Gochnatia lanceolata Beltram & Ferreyra, with glabrous leaves. The species has been transferred to a new genus Paquirea (Panero and Freire 2013).

Key to
The gnarled appearance of the stems was found in the newly described G. recticulifolia and in one specimen of G. arequipensis Sandwith. The lack of this character in all other collections of Gochnatia may be an artifact of collecting and it may occur in other species but was omitted during the pressing of the plants.