Kadenicarpus pseudomacrochele

Name and subspecies

Kadenicarpus pseudomacrochele occurs naturally in northeastern Mexico. It was initially described as Strombocactus pseudomacrochele. The name Turbinicarpus pseudomacrochele, common in the literature, is now a synonym. POWO accepts three subspecies, K. pseudomacrochele subsp. pseudomacrochele, subsp. krainzianus and subsp. minimus. [2-WWW]

The former Turbinicarpus pseudomacrochele subsp. lausseri is a synonym in POWO of the nominate subspecies, Kadenicarpus pseudomacrochele subsp. pseudomacrochele. Descriptions published under lausseri concern material distinguished by their authors within this accepted subspecies. [2-WWW]

The 2019 publication discusses sites of the complex in Hidalgo and Querétaro, including near Zimapán. The spine study included several separately identified batches, including material of subspecies minimus from seeds TCG 9101 originating from Davoxtha in Hidalgo. Spine-anatomy results for this subspecies refer to its sample. [Vázquez-Sánchez et al. 2019, Vázquez-Sánchez et al., p. 415. Mosco, p. 121, Table 1] [Mosco 2009, Vázquez-Sánchez et al., p. 415. Mosco, p. 121, Table 1]

Whole-plant structure and flower variation

In the regional flora, plants described as Turbinicarpus pseudomacrochele (now Kadenicarpus pseudomacrochele) are solitary or produce offsets at the base. Stems are spherical to flattened, usually up to 5 cm high and 4 cm in diameter, with a sunken base. They have a green surface and prominent tubercles arranged in rows. Narrowly elliptical areoles produce 6–12 awl-shaped spines up to 3 cm long. Young spines are yellow, then become greyish brown or black. [Arias and Aquino 2019, p. 274–275]

The flower description usually includes a length of 2–3.2 cm and width of 2.4–3.5 cm, with extremes reaching 4 cm. Inner tepal colour varies from white with a pink stripe, through intense pink, to yellow. Bare, spherical fruits are brown and measure 4–6 mm. Black seeds are around 1.2 mm long. These ranges come from a historically broad regional description in which different colours were associated with subspecies. [Arias and Aquino 2019, p. 274–275]

For the nominate subspecies, the flora gives stems up to 6 cm tall and a light pink perianth with a white margin. Plants grew in dry scrub of central Querétaro at 1900–2000 m, and flowering was recorded from February to March. Material identified as subsp. krainzianus had dark green stems up to 4 cm tall and yellow flowers 2–2.3 cm long. It occurred in similar scrub at around 1900 m. This describes material under that identification, now belonging to K. pseudomacrochele subsp. krainzianus. [Arias and Aquino 2019, p. 275–277]

Szczeciniaste ciernie podgatunku minimus

In K. pseudomacrochele subsp. minimus (called Turbinicarpus pseudomacrochele subsp. minimus in the study), the radial spines examined had a bristle-like texture and blunt tips. The epidermis was continuous, with feathery projections. Internal fibres had relatively thin walls, which the author linked to the delicate form of the whole spine. [Mosco 2009, p. 121–123, tab. 2]

In other taxa of this complex studied, the surface also formed projections, with varying arrangements of cells and spaces between them. The description of one subspecies develops the features of the whole complex, but its fibre parameters remain assigned to the identified material. The source table retains this scope. [Mosco 2009, pp. 123–127]

Surface tissues and crystals

In subspecies minimus, the hypodermis had thin cell walls. Prismatic crystals occurred in this layer, while the pith contained druses. The study therefore showed two crystal types simultaneously present in different stem locations. The hypodermal feature supported recognition of the Kadenicarpus lineage, while the pith feature illustrated variation among its members. [De la Rosa-Tilapa et al. 2019, wersja online, p. 2]

Cortical vascular bundles contained xylem fibres, while the main stem xylem was fibre-free. Cork cells of older portions had thin walls. Seed, bundle and hypodermal structure together formed a combination distinguishing the Kadenicarpus studied from the other former turbinicarpi. [De la Rosa-Tilapa et al. 2019, De la Rosa-Tilapa et al., online version, pp. 2–4. Vázquez-Sánchez et al., p. 412] [Vázquez-Sánchez et al. 2019, De la Rosa-Tilapa et al., online version, pp. 2–4. Vázquez-Sánchez et al., p. 412]

Seeds and complex boundaries

Seed-surface microsculpture is smooth, and the micropyle and funicular scar form a shared region. This structure was compared with DNA data in the 2019 analysis. However, the subspecies of the complex studied did not form a group matching all taxon boundaries recognised then. The authors indicated the need for a larger sample of natural populations to explain their relationships. [Vázquez-Sánchez et al. 2019, p. 409, 412, 414, 416–417]

The current acceptance of three subspecies in POWO forms the nomenclatural basis of this account. Subspecies identification and material provenance remain significant when using older spine descriptions. The result of a poorly resolved analysis and current name status describe two different parts of knowledge about the complex, its studied relationships and current classification treatment. [2-WWW] [Vázquez-Sánchez et al. 2019]

Related articles

Materials from the author's archive

The species also appears in Konrad Szychowski's private material archive. [Kaktusy i Inne 2005a, file p. 53]