Cryptanthaacrimuricata (Boraginaceae), a distinctive new taxon of series Muricatae

Abstract

In the process of studying the species Cryptanthamuricata and its varieties, we discovered a unique taxon of the genus that resembles C.muricata but differs in having a mostly densely white-strigose stem vestiture (sometimes with spreading trichomes) and tuberculate to muricate nutlets with often whitish tubercles that are, in comparison with typical C.muricata, larger, with a wider base and more pointed apex, and more densely spaced. We believe this form to be different enough to describe as a new species, Cryptanthaacrimuricata. This new species occurs in southwestern North America: in California and Arizona of the United States and in northern Baja California, Mexico. It occurs in mid- to relatively high elevation mountain regions of mostly desert transition/escarpment in the Transverse and Peninsular Ranges, in the Sonoran and Mohave Deserts, and with some populations scattered in the southern Sierra Nevada. We believe this new species to be closely related to C.clokeyi, C.martirensis, C.muricata, and possibly C.hooveri, of Cryptantha series Muricatae. Detailed molecular phylogenetic are needed to better establish their interrelationships.

Keywords: Boraginaceae; Cryptantha; Cryptanthamuricata; series Maritimae; series Muricatae; taxonomy.

Figure 1.

Cryptanthaacrimuricata. Images of collection: M.G. Simpson 4186, 14 April 2019, SDSU22965 A herbarium specimen. Note dominant primary stem terminating in bifurcate cymules B–E, H, I field photographs B primary stem, showing cauline leaves and lateral branches C close-up of primary stem, the vestiture primarily strigose plus scattered spreading-hirsute D extreme close-up of primary stem, showing predominantly whitish strigose vestiture (trichomes antrorsely oriented) E close-up of cymule tip, showing relatively small corolla, this one slightly < 2 mm wide F, G flower removed and dehydrated F corolla, showing fornices, anthers adnate to corolla tube, and basal appendages G gynoecium, showing 4-lobed ovary, gynobasic style, and discoid stigma H cymule of primary stem I close-up of mature fruiting calyces. Note ovoid shape and spreading-hispid, pustulate trichomes of thickened sepal midribs.

Figure 2.

Cryptanthaacrimuricata. Images from holotype specimen: J.M. André 40457, 10 May 2019, RSA0633491 A nutlet, in (left to right) dorsal, ventral, and lateral views. Note ovate shape (dorsal and ventral outlines); truncate base; thickened, “toothed” or “beaded” margins; whitish, conic surface tubercles; and narrow ventral groove, which is widely bifurcate at the base, delimiting small areole B fruiting calyx, showing appressed marginal trichomes and spreading hispid along midrib C fruit opened, showing prominent style, protruding well beyond nutlets D herbarium specimen.

Figure 3.

Distribution maps of Cryptanthaacrimuricata from specimens cited here, plus of the three varieties of C.muricata from preliminary data, in two scales A showing overall distribution and B in a larger scale map highlighting the Transverse Ranges and northern Peninsular Ranges. See text for distribution summaries of the taxa. Arrow indicates location of holotype/isotypes specimens of Cryptanthaacrimuricata. Map data @2024 Google, INEGI.

Figure 4.

Nutlets (dorsal view at left, ventral at right) and stem morphology of the three recognized varieties of C.muricata, series MuricataeACryptanthamuricatavar.denticulataBCryptanthamuricatavar.jonesiiCCryptanthamuricatavar.muricata. Accession numbers of specimens sampled indicated. Note variation in nutlet sculpturing and stem vestiture that is strigose and hispid.

Figure 5.

A, B Nutlets (dorsal view at left, ventral at right) and stem morphology of three additional Cryptantha species of series MuricataeACryptanthaclokeyiBCryptanthamartirensisCCryptanthahooveri, tentatively placed in series. Accession numbers of specimens sampled indicated.