Licaria ramiroi Cuevas, 2023

Cuevas Guzman, Ramon, Sanchez-Rodriguez, Enrique V. & Morales-Arias, Jose Guadalupe, 2023, Licaria ramiroi (Lauraceae), a new species from Western Mexico, PhytoKeys 218, pp. 69-78 : 69

Licaria ramiroi Cuevas sp. nov.

Figs 1 , 2

Diagnosis.

Licaria ramiroi is similar to L. triandra (Sw.) Kosterm. but differs from the latter by leaves with 12-23 pairs of secondary veins (vs. 5-10); inflorescence surface commonly glabrous (vs. sparsely to densely appressed pubescent); entire hypanthium sericeous inside (vs. glabrous); stamens with free anthers (vs. stamens with anthers fused at least in their basal half).

Type.

Mexico. State of Jalisco: Municipality of Casimiro Castillo, cañada El Tecolote , 19 July 2022 (fl), R. Cuevas G., E.V. Sánchez R. & J.G. Morales A. 14182 (holotype ZEA; isotypes to be distributed) .

Description.

Trees 10-26 m in height, trunk 15-60 cm in diameter; bark flaky and peeling off in irregular layers, the outer reddish-brown, the inner yellow, turning pink as it oxidises. Branchlets cylindrical, 1.5-2 mm thick, brownish-grey, lenticellate and exfoliating, glabrous; axillary buds conical, 1.5-2 mm in length, 1 mm in width, glabrous; terminal buds cylindrical, 7-12 mm in length, 1 mm in width, reddish, glabrous. Leaves alternate, reddish when sprouting, mature leaves lanceolate to oblong, 7-16 × 1.3-4.7 cm, 3-6 times longer than wide, chartaceous, glabrous on both sides; base cuneate, sometimes obtuse; margins entire, sclerotic; apex acuminate; the secondary veins are inconspicuous, but recognisable on both sides, whereas the higher-order venation is not resolved, mid-vein depressed above and protruding below, secondary veins 12-23 pairs; petioles sulcate adaxially (4-) 7-12 × 1-1.8 mm, glabrous. Inflorescences axillary, paniculate-cymose, branched from near the base, rarely solitary, 1-4 cm in length, the terminal flowers often fused at their bases; peduncles 1-2 mm in length; bracts soon deciduous, concave, ovate-lanceolate, 0.7-1.9 × 0.4-0.8 mm, glabrous. Flowers ellipsoid or obovoid, 2.5-3 mm in length; pedicels 1.2-1.8 mm in length, glabrous; hypanthium 1.4-2.1 × 1.9-2 mm, externally glabrous, internally sericeous; tepals 6, fused to 1/4 of their length in the basal part, imbricate, ovate, subequal (inner ones slightly smaller), 0.8-1.3 × 0.8-0.9 mm, concave, inconspicuously fimbriated on their margins; stamen series I and II lacking; androecium with 3-5 stamens, exserted, fused at the filaments only, tomentose on both sides of filaments, 1.2-2.4 mm in length, anthers bisporangiate, ovate to oblong, tomentose at the base on the adaxial face, the rest glabrous, 1.1-1.3 × 0.8-0.9 mm, sporangia on the abaxial side of the anther, each sporangium with an oblique locule covering most of the anther body, sometimes the locule sagittate or irregular i.e. two locules fused, valves extrorse and remaining at the apex of the anther; 4-8 glands observed, at the base of the filaments or slightly above, sometimes contiguous glands fused at their bases, but with clearly separated apices, lanceolate to ovate or irregularly shaped, lamellar, 0.4-0.6 × 0.2-0.4 mm, pubescent at their base; pistil elongate, 2.3-2.7 mm in length, glabrous, ovary 0.8-1 × 0.6-0.7 mm. Fruit ellipsoid, purple with a yellow base when mature, 20-28 × 12-15 mm, glabrous; cupule lenticellate, 12-14 mm in height, 14-18 mm in diameter at apex, 7-10 mm in depth, double-rimmed, outer margin slightly ascending to spreading, wavy, the inner margin erect, entire, 0.5-1 mm in height; pedicel in fruit turbinate, 3-5 mm in length, 3-4.5 mm in diameter distally, 1.5-2 mm basally.

Distribution and ecology.

Licaria ramiroi is known from only one locality in the Sierra de Manantlán, Jalisco, Mexico. It has been recorded between 1000 and 1600 m in elevation in an ecotone between subdeciduous tropical forest and montane cloud forest. Dominant trees in this habitat correspond to individuals of the Lauraceae family, such as Beilschmiedia manantlanensis Cuevas & Cochrane, Damburneya rudis (C.K. Allen) Trofimov & Rohwer and D. salicifolia (Kunth) Trofimov & Rohwer. Other tree species observed are Amyris mexicana Lundell, Aphananthe monoica (Hemsl.) J.-F. Leroy, Calatola laevigata Standl., Cedrela odorata L., Drypetes gentryi Monach., Myrcianthes fragrans (Sw.) McVaugh, Prunus cortapico Kerber ex Koehne, Sideroxylon brucebenzii Cuevas & A. Vázquez, S. portoricense Urb. and Trophis mexicana (Liebm.) Bureau. Hemi-epiphytes are represented by Balmea stormiae Martínez, Ficus aurea Nutt., Oreopanax echinops (Schltdl. & Cham.) Decne. & Planch. and Oreopanax sanderianus Hemsl. and vines by Solandra maxima ( Sessé & Moc.) P.S. Green.

Field observations were carried out for three years; as we found no flowers or fruits during the different seasons of the year, nor observed any seedlings, in this period, this leads us to suggest that this species could have supra-annual flowering and fruiting periods.

The locality from where the new species of Licaria is described is an area that has been prominent for records of new species, such as Beilschmiedia manantlanensis (Cuevas & Cochrane, 1999), Sideroxylon brucebenzii (Cuevas & Vázquez-García, 2021) or disjunct distributions, such as those of Desmopsis trunciflora (Schltdl. & Cham.) G.E. Schatz ( Cuevas et al. 2002) and Nectandra rudis C.K. Allen ( Cuevas et al. 2008), amongst others. Fortunately, the area forms part of the Sierra de Manantlán Biosphere Reserve, ensuring a certain degree of conservation of the flora of this area, which is notable in the region for its uniqueness and the distribution of some of its species ( Cuevas 2002).

The species has been recorded in flower in the months of July-August and with ripe fruits from February to March.

Etymology.

The species honours the memory of Ramiro Cuevas Guzmán, dear brother of the first author, a person who loved the countryside and who collected plants for more than 30 years together with the author of the species, in various regions of the southern coast of Jalisco. Several of these collections are deposited in national herbaria and some have resulted in scientific novelties.

Preliminary conservation status.

According to the Categories and Criteria of the IUCN Red List ( IUCN 2012), L. ramiroi is assigned a preliminary status of "Critically Endangered" CR B2a C2a(ii). The known and estimated geographical distribution of this species is less than 10 km2 in area and it has been recorded at only one locality, with a population size estimated at fewer than 250 mature individuals. Moreover, it should be noted that there is little natural regeneration of the species and few juvenile individuals present.

Additional specimens examined.

Mexico: State of Jalisco: Municipality of Casimiro Castillo: cañada El Tecolote , 19°36'55"N, 104°18'27"W, 13 December 1998 (st), R. Cuevas, L. Guzmán & J. Aragón 6374 (ZEA); R. Cuevas, L. Guzmán & J. Aragón 6367 (ZEA); cañada El Tecolote, 19°37'06"N, 104°19'29"W, 14 December 1998 (st), R. Cuevas, L. Guzmán & J. Aragón 6413 (ZEA); cañada de La Naranjera, 19°37'20"N, 104°20'38"W, 23 February 1999 (ripe fr), R. Cuevas, L. Guzmán & J. Aragón 6571 (ZEA); cañada de La Naranjera, 19°37'21"N, 104°20'33"W, 24 February 1999 (ripe fr), R. Cuevas, L. Guzmán & J. Aragón 6591 (ZEA); barranca de La Naranjera, 19°36'55"N, 104°18'27"W, 11 July 1999 (immature fr), R. Cuevas, L. Guzmán, C. Palomera & J. Aragón 6819 (ZEA); 19°36'55"N, 104°18'27"W, 11 July 1999 (fl), R. Cuevas, L. Guzmán, C. Palomera & J. Aragón 6820 (ZEA) .

Notes.

Due to its erect tepals, the exserted stamens with their filaments fused at the base, the anthers with large locules orientated in the longitudinal axis of the flower, with the valves opening upwards, Licaria ramiroi is classified in the subgen. Licaria , within the group of species with exserted stamens and with the locules on the external surface of the anthers ( Kurz 2000). Morphological characters with narrow leaves with 12 or more secondary veins, the shape and size of the flowers, exserted stamens and the large sporangia covering most of the anther body and running lengthwise to the flower axis, relate Licaria ramiroi to L. Licaria siphonantha Lorea-Hern. but separates from this species by its fused tepals at its base, generally shorter and glabrous inflorescences, free anthers and the hypanthium internally sericeous (see Table 1 ). The shape and size of the flowers, the tepals fused at their bases, the glands often fused at their bases with free apices, the size of the cupules in the fruit with strongly undulating margins, as well as the shape and size of the fruit, relate L. ramiroi with the variable L. triandra (sensu Kurz (2000), including L. cervantesii (Kunth) Kosterm. and Misanteca nayaritensis Lundell), the only species of Licaria recorded for western Mexico ( Kurz 2000), from which it is separated by the presence of stamens fused only in the filaments, while the anthers are generally free, an internally sericeous hypanthium and other characters that are presented in Table 1 .

A review of 60 flowers from two individuals (20 from one and 40 from the other) collected 23 years apart, suggests that the proportion of flowers with 3, 4 and 5 stamens in whorl III is more or less equal. This phenomenon observed in L. ramiroi is something previously not recorded in the genus Licaria . The evidence supporting the notion that they are all stamens of whorl III is that all of the anthers are extrorse and there is incomplete separation of stamen primordia and, when this occurs, some of these stamens can show a certain degree of fusion at the base of the anthers (see Fig. 2 ). Gradation is also observed in the locules that show an incomplete separation during development, sagittate locules and others with an irregular shape. Between four and eight glands were observed in L. ramiroi , some of them free and others fused at their bases, but always with clearly separated apices (Fig. 2 ). In L. ramiroi , the development of more than three fertile stamens in whorl III, with the corresponding increase in glands, could be a teratological condition due to an environmental response, possibly to the infection of Diptera larvae, which were observed parasitising some of the dissected flowers. To determine if the aberrations observed in the flowers of the species are due to the presence of the indicated parasites, further research will be required.

Licaria has been a well-defined genus by its three bisporangiate fertile stamens in whorl III, the presence or absence of staminodes in whorls I and II and the lack of staminodes in whorl IV, a deep receptacle and a double-margined cupule ( Kurz 2000). Recent molecular studies have recovered a clade within the Ocotea complex called " Licaria group and allies", which includes, in addition to Licaria , other genera with deep receptacles and a double-margined cupule, including species of Ocotea Aubl., Aniba Aubl., Dicypellium Nees & Mart., Kubitzkia van der Werff, Paraia Rohwer, H.G. Richt. & van der Werff and Urbanodendron Mez ( Trofimov et al. 2019).

The double-margined cupule in L. ramiroi suggests a morphological connection to species in genera such as Aiouea Aubl., Damburneya Raf. and Mespilodaphne Nees & Mart., especially with those with bisporangiate anthers. However, the species of these genera present other characteristics that are not recorded in L. ramiroi , such as the fact that, in Aiouea , there are staminodes in the fourth androecial whorl that show a large glandular head, generally chordate to sagittate ( Rohde et al. 2017); in Damburneya , the tepals are adaxially pubescent at the base and generally papillose towards the tips ( Trofimov et al. 2016) and both genera have nine fertile stamens, occasionally six or three in Aiouea . Mespilodaphne , on the other hand, is a recently reinstated genus, it presents flowers with spreading tepals, tongue-shaped stamens, heavily papillose and tetrasporangiate ( Trofimov et al. 2019). Mocinnodaphne Lorea-Hern., recently included in Aiouea , meets most of the characters of Licaria , with the exception of having well-developed staminodes in whorl IV ( Lorea-Hernández 1995). Due to a set of characters present in L. ramiroi , such as its deep receptacle, fertile stamens in the III whorl, bisporangiate, cupule with double margin, lack of staminodes in the first two whorls and the fourth, we consider that the best inclusion of the species is in Licaria .

Understanding the morphological complexity of the " Licaria group and allies" within the Ocotea complex and taking into account the androecial morphology recorded in L. ramiroi , considering that it is a genetic condition, then the species could be relocated to another genus within the Ocotea complex, but it would be necessary to wait for the species to be included in some molecular study to better define its phylogenetic relationships.

Figures

Figure 1. Licaria ramiroi Cuevas sp. nov. A branchlets with inflorescences B branchlets with immature fruit C close-up image of an inflorescence D inflorescence with flowers in top and side view, with the two terminal flowers fused at their bases E side view of flower F flower in tangential section showing pistil and sericeous internal surface of hypanthium G upper frontal view of a flower with stamens the tepals opened artificially H Pair of stamens in adaxial view I Pair of stamens in abaxial view.

Figure 2. Licaria ramiroi Cuevas sp. nov. A stamen with two pairs of glands B ring of stamens, with the anthers showing locules and valves and three glands in the base C three stamens of a flower, one showing a sagittate locule (left), the other with an irregular locule (right) and several glands D four stamens of a flower with several glands E five stamens of a flower F fruits with their cupules G one fruit and two cupules, showing the outer and inner margins.