Holographis verticillata (Hemsl.) T.F. Daniel, L.A. McDade, and C.A. Kiel, 2020

Daniel, Thomas F., McDade, Lucinda A. & Kiel, Carrie A., 2020, Aphelandra verticillata transferred to Holographis (Acanthaceae: Acantheae), Proceedings of the California Academy of Sciences 66 (11), pp. 299-304 : 299-303

Holographis verticillata (Hemsl.) T.F. Daniel, L.A. McDade, and C.A. Kiel , comb. nov.

Aphelandra verticillata Hemsl. , Biol. Centr. Amer. Bot. 2:513. 1882. Crossandra haenkeana Nees in Alph. de Candolle, Prodr. 11:281. 1847, non Aphelandra haenkeana Nees, 1847 .

Type.— MEXICO. Western Mexico , 1791, T. Haenke s.n. (holotype: PR!; isotypes: GZU!, PRC!) .

Descriptions of the species were provided by Wasshausen (1975) and Daniel (1991). Occurrences are known from four states in south-central Mexico (Guerrero, México, Michoacán, and Morelos; Daniel 1991). Although there are no illustrations of the species, plants were recently photographed in the southeastern-most portion of the state of México ( Fig. 1 ).

The following additional collections have been studied since those cited by Daniel (1991). The distribution of this species, which is endemic to central Mexico, is shown in Figure 2.

ADDITIONAL SPECIMENS EXAMINED.— Guerrero: Mpios. de Iguala y Buenavista, Cañón de la Mano, entre Los Amates y El Naranjo, 10 km N de Iguala por el ferrocarril, sobre el cerro a SW de Los Amates, [ca. 18°24ʹ50.86ʺN, 099°29ʹ34.64ʺW], C. Catalán C. 369 ( L, MEXU, MO), 509 ( MO); Mpio. Eduardo Neri , Cañada Carrizalillo, 1 km ESE de Amatitlán, 17°52ʹN, 99°45ʹW, R. Cruz D. 616 ( FCME); Mpio. Taxco de Alarcón , 1 km N de La Cascada, 18°33ʹ26ʺN, 99°39ʹ35ʺW, R. Cruz D. 2122 ( FCME); Mpio. Taxco , alrededores de Acuitlapan, B. del Río Luyando s.n. ( FCME). México: Tlatlaya y cercanías, E. Matuda et al. 29997 ( MEXU). Morelos: Mpio. Xochitepec, E de Xochitepec a 100 m del Río Tetlama en la falda del Cerro El Capire, I. de la Cruz 1527 ( MEXU).

AUTHORSHIP AND TYPIFICATION.— Authorship of Aphelandra verticillata has been cited as “Nees ex Hemsl.” (e.g., Wasshausen 1975; Daniel 1991) and as “Nees” (e.g., IPNI 2019). In the protologue of Crossandra haenkeana, Nees (1847) cited in synonymy “ Aphelandra verticillata N. ab E. in h. Haenk.!” using the name he wrote on some specimens of Haenke’s type collection. Owing to the prior existence of A. haenkeana Nees, Hemsley (1882) effectively published a new name for this species on its transference to Aphelandra , using the epithet of the name published as a synonym by Nees in 1847. Therefore, the publishing author of the name A. verticillata is Hemsley (or potentially “Nees ex Hemsl.”), but not Nees.

Wasshausen (1975) indicated that the holotype of Aphelandra verticillata was Haenke s.n. at PR and so annotated a collection there, which is mounted on two sheets (one bearing an original label with “ Aphelandra verticillata N. ab E., Mexico, H. Haenke,” all in Nees’ handwriting, and the other bearing only plants and annotation labels). In the protologue of Crossandra haenkeana, Nees (1847) indicated merely a Haenke collection from Mexico in Haenke’s herbarium on which he had written “ Aphelandra verticillata N. ab E.” The “original herbarium” or “main set” of Haenke’s herbarium has been indicated to be at PR (e.g., Lanjouw and Stafleu 1957; Stearn 1973). Both sheets at PR bear the same pair of reference numbers (305357 and 10480) to which “ A ” has been added on the label-bearing sheet and “ B ” has been added to the second sheet. In 1990, Daniel annotated both of these sheets as constituting the holotype. At PRC there are two isotypes, one of which (barcode 454829) bears “ Aphelandra verticillata N. ab E.” in Nees’ handwriting. The isotype at GZU (acc. 250616), also bears “ Aphelandra verticillata N. ab E.” in Nees’ handwriting; in 2011, this specimen was erroneously annotated by Daniel as “ Aphelandra haenkeana ,” and as a probable isolectotype of C. haenkeana . Lectotypification would not appear to be necessary for the basionym of A. verticillata ; however, if it is (e.g., if one interprets that Nees saw in Haenke’s herbarium all three of the specimens noted to bear the label data in his handwriting [i.e., those known to be at P, PRC, and GZU] and then these were subsequently dispersed with a division of Haenke’s herbarium, one of them might have to be designated as the lectotype), Wasshausen’s (1975) indication of the holotype at PR would serve to effectively lectotypify the name.

KEY CHARACTERISTICS. — The following key summarizes the known macromorphological, palynological, and cytological differences and tendencies that help to distinguish Holographis and Aphelandra :

1a. Leaves opposite (rarely subopposite) or quaternate; bracts entire and usually green; corollas often with colored linear nectar guides, 6.5–24 (– 40 in H. velutifolia and H. verticillata , both of which have quaternate leaves) mm long; filaments of stamens often entirely included in corolla tube; pollen with colpi sometimes expanded or bifurcating toward poles, interapertural exine homogeneously sculptured; x = 13............................. Holographis

1b. Leaves opposite (rarely subopposite); bracts entire or dentate, green or variously colored; corollas rarely with linear nectar guides, mostly 25–85 mm long; at least distal portion of filaments of stamens usually exserted from corolla tube; pollen with colpi not expanded or bifurcating (usually narrowed) toward poles, interapertural exine usually heterogeneously sculptured; x = 14............................................................... Aphelandra

Morphological characteristics of H. verticillata that are suggestive of Aphelandra include a reddish coloration sometimes present on the bracts, relatively elongate corollas (25–38 mm long), and filaments and anthers of stamens exserted well beyond the mouth of the corolla. Each of these traits is also encountered in one or more species of Holographis . Characters of H. verticillata more typical of species of Holographis include its quaternate leaves (characteristic of 13 species of the genus, but unknown in Aphelandra ) and pollen with homogeneous exine and colpi that expand or bifurcate toward the poles (known in at least five species of the genus, but essentially unknown in Aphelandra ; see discussion of pollen below). Holographis verticillata can be distinguished from its congeners by the combination of having whorled leaves, elliptic bracts that are 11–19 mm long, yellow corollas that are 25–38 mm long, and pubescent capsules.

POLLEN.— Although there is variation in exine sculpturing among species of both Aphelandra (e.g., Wasshausen 1975; McDade 1984; Daniel 1991, 1998) and Holographis (e.g., Daniel 1983, 1988, 1998), at least two characteristics of pollen of H. verticillata more closely resemble grains of Holographis than those of Aphelandra bearing three colpi ( Fig. 3 ). Like that of H. verticillata , pollen of at least five species of Holographis (e.g., H. anisophylla T.F. Daniel , H. hintonii (Leonard) T.F. Daniel , H. ilicifolia Brandegee , H. pallida Leonard & Gentry , H. virgata (Harv. ex Benth & Hook.f.) T.F. Daniel ) have colpi that expand or bifurcate toward the poles. Colpi in most species of Aphelandra that bear three colpi either taper or do not expand poleward; distally bifurcating colpi have been documented in this genus only in some plants of A. golfodulcensis McDade ( McDade 1984: fig. 26). It is noteworthy that colpi that expand toward the poles are also known in Stenandrium (e.g., S. goiasense Wassh., Wasshausen 1990 : fig. 2c; some specimens of S. dulce (Cav.) Nees, Daniel 1998 : fig. 2g), a Neotropical genus more closely related to Holographis than Aphelandra based on both molecular phylogenetic data ( McDade et al. 2005) and putative base chromosome numbers ( Daniel 1991; i.e., x = 13 in Holographis and Stenandrium vs. x = 14 in Aphelandra ). The second characteristic linking pollen of H. verticillata to Holographis is the interapertural exine sculpturing. In all species of Holographis , including H. verticillata , the interapertural exine is homogeneously sculputured, whereas in many or most species of Aphelandra with 3- colpate pollen, it is heterogeneous ( Fig. 3 ).

Wasshausen (1975: fig. 18) shows pollen of A. verticillata (putatively of Moore 5503 at US) that differs by having 3-colpate pollen with colpi tapering toward the poles, a prominent ridge within each colpus, and a 3-parted polar aperture. Similar pollen with intracolpal ridges and/or 3-parted polar apertures (cf. Daniel 1991: figs. 2e, g) are known among several species of Aphelandra , but not among any currently recognized species of Holographis . Examination of pollen from Moore 5503 at UC confirms pollen without intracolpal ridges or 3-parted polar apertures and with colpi expanded toward the poles ( Fig. 3D ). The image shown by Wasshausen (1975) likely represents contamination from a species of Aphelandra .

Figures

FIGURE. 1. Holographis verticillata. Vegetative node showing quaternate leaves (top left). Habit with inflorescence (top right). Inflorescence (center left). Head-on view of floral limb (center). Upper lip of corolla with stamens and style/stigma (center right). Flower and buds on inflorescence with bracts and bracteoles (bottom). Photos courtesy of Dale Denham.

FIGURE 2. Map of central Mexico showing the distribution of Holographis verticillata.

FIGURE. 3. Examples of pollen of Holographis (including H. verticillata) and Aphelandra. A, B. Holographis pallida Leonard & Gentry (Daniel 3382 from Sonora): A. Apertural view; B. Interapertural view. C, D. Holographis verticillata: C. Apertural view (Daniel et al. 3295 from Michoacán); D. Interapertural view (Moore 5503 from Guerrero). E, F. Aphelandra castaneifolia Britton (Daniel & Wood 10175 from Bolivia): E. Apertural view; F. Interapertural view. Scales = 5 µm.