Paepalanthus sessiliflorus var. sessiliflorus Mart. ex Körn.

Andrade, Maria José Gomes De, Trovó, Marcelo, Rocha, Lamarck & Giulietti, Ana Maria, 2022, Paepalanthus (Eriocaulaceae) without scapes and spathes, a survey with the description of a new species, Phytotaxa 560 (2), pp. 135-152 : 143-146

2.1. Paepalanthus sessiliflorus var. sessiliflorus Mart. ex Körn. in Martius, Fl. Bras. 3(1): 361. 1863.

Lectotype (designated by Moldenke 1976b):—[ BRAZIL] “Crescit in prov. Bahiensis campis haud procul a mari prope praedium Caballo”, s.d., Luschnath 33 in Martius Hb. Fl. Bras. 557 ( M [0165226]!, isolectotypes B [10 0247672-a]!, B [10 0247672-b]!, BM [000938297]!, BR [0000008619570]!, BR [0000008619587]!, HAL [0109753]!, K [000293242]!, MO [202612]!, NY [00102939]!, NY [00102940]!).

( Figures 2G , 3 , 4L–M , 5J–N ).

The name Paepalanthus sessiliflorus was initially suggested in manuscripts and annotated in specimens by Martius, but was only validly published by Körnicke (1863: 361), who cites two different collection numbers Luschnath 33 and Mart. Hb. Fl. Bras. 557. These numbers are in fact the same collection, as suggested by the specimens at BR. One of the herbarium sheets kept at BR contain both original labels Luschnath 33 and Mart. Hb. Fl. Bras. 557, with the first including the original location description. The other specimen contains one original label Mart. Hb. Fl. Bras. 557 indicating Luschnath as the collector. The label Mart. Hb. Fl. Bras. 557 represented Martius’s personal numbering system. The specimen at B is a single sheet with two labels, but in this case, there is a later attempt to segregate both collections. The remaining material was distributed to various herbaria labelled only as Mart. Hb. Fl. Bras. 557. Moldenke (1976b) explicitly refers as type the specimen Luschnath 33 (distributed as Martius 557) housed at M, and as isotypes the specimens at B, and BR (2x). According to the current ICN ( Turland et al. 2018), Moldenke type citation is to be followed as an inferential lectotype (articles 7.11, 9.10, and 9.23).

Paepalanthus sessiliflorus is mainly distinguished by its annual dwarf 0.6–2.0 cm long habit; erect stem with persistent, recurved, lanceolate, leaves 3.0–5.0 mm long, and blade almost indistinguishable from the sheath, margin ciliate in the basal half, with obtuse to acute apex, the apical leaves slightly to twice as long as the floral disc. These characters are present in both varieties, however there are few differential morphological characters according to Moldenke (1974) and Hensold (1999).

Körnicke (1863) described the seed as subrounded, brown and glabrous. Using SEM, the seeds are obovate, ca. 0.4 mm long, seed coat with primary sculpture with a reticulated pattern, cells 4-5 walled, the longitudinal anticlinal walls more prominent than the transverse walls, giving rise to longitudinal ribs along the seed coat ( Figures 5M–N ). This seed coat pattern is similar with that of Paepalanthus perpusillus Kunth (1841: 503) (see Giulietti et al. 1988), but it is different from P. pagannucii , all three species included in Paepalanthus series Leptocephali .

Paepalanthus sessiliflorus var. sessiliflorus ( Figure 2G ) is endemic to Brazil, mostly distributed in sandy soils of the restingas of Bahia and Sergipe states, with populations occurring also in the northern part of the Espinhaço Range in Bahia ( Figure 3 ). Field observations and the analysis of recent and historical collections of this variety reveal few morphological differences between the populations found in the costal sand dunes, and the campo rupestre. The campo rupestre plants are usually larger (1.5–2 cm long), and the inner involucral bracts can be ciliate. In this treatment, this is interpreted as within the range of morphological variation of a single taxon, especially because all specimens seen have the same seed coat pattern.

Additional selected material examined:— BRAZIL. Bahia: Itamaraju, 12August 1995, Hatschbach et al. 63034 ( MBM); Lençois, Capitinga , 12°30’S, 41°23’, 15 August 2006, F . F . Rocha 63 ( HUEFS); Maraú , povoado de Saquaira, 15 August 1999, J . G . Jardim 2237 ( HUEFS, NY); Rio de Contas, Serra Marsalina , campo cerrado, 16 August 2006, M . J . G. Andrade et al. 623 ( HUEFS); Pico das Almas, campo rupestre, R . M . Harley et al. 53657 ( HUEFS); Salvador , 30 September 1984, L . P . Queiroz 880 ( HUEFS) . Sergipe: Indiaroba, 16 August 201, A . P . Prata et al. 2824 ( ASE) .

Figures

FIGURE 2. Life-forms and inflorescences in Paepalanthus species without scape. A–B. Paepalanthus leucocephalus growing in the Chapada Diamantina, BA. C–E. P. paganuccii. C. Population growing in Tocantins (Harley 56669) on sandy soil. D. Rupiculous individual growing on sandstone. E. Detail of the capitulum. F. P. scleranthus, growing in Diamantina, MG, showing the black capitula. G. P. sessiliflorus growing in campo rupestre in Pico das Almas, BA. Scale bar: 5 mm. (photo credits: A–B. C.N. Fraga, C–E, G. R.M. Harley, F. M. Trovó).

FIGURE 3. Geographical distribution of Paepalanthus species without scape. Red-orange symbols = Paepalanthus ser. Leptocephali; Blue-green symbols = P. subg. Thelxinoë.

FIGURE 5. SEM micrographs. A–I: Paepalanthus paganuccii. A. capitulum rounded by the terminal leaves. B. leaf with filamentous trichomes. C. leaf margin showing tricellular filamentous trichomes with a ring on the apex of the basal cell. D. staminate old flower showing bract with trichomes, calyx and involute corolla. E. pistillate flower showing three ciliate petals and gynoecium with stigmatic branch, lacking nectariferous branches. F. detail of petal apex showing 1-3-celled filamentous trichomes, basal cell with ring. G. detail of the floral bract apex showing 4-5-celled filamentous trichomes. H–I. mature seed, seed coat with a tuberculate-striate pattern, with the long tubercule organized in rows. I. detail of the seed coat showing the elongate tubercules. J–N: Paepalanthus sessiliflorus. J. a complete individual plant. K. staminate old flower showing long ciliate floral bract and calyx. L. pistillate flower showing three ciliate petals and gynoecium with stigmatic branch, lacking nectariferous branches. M–N. mature seed, seed coat with a reticulate pattern. N. detail of the seed coat showing cells 4-5-walled, the longitudinal anticlinal walls more proeminente than the transverse walls (A–I. Queiroz 10917, J. Queiroz 880, K. Harley 53657, L–N. Andrade 623).

FIGURE4.MorphologyofplantandflowersinPaepalanthuswithoutscape.A–K:Paepalanthuspaganuccii.A.habit.B.leaf.C.capitulum. D. involucral bract of the outer series. E. involucral bract of the inner series. F. open staminate flower showing calyx, anthophore, corolla, androecium and floral bract. G. closed staminate flower showing pedicel, calyx and corolla trichomes. H. open pistillate flower showing calyx, corolla, gynoecium and floral bract. I. sepal. J. petal. K. developing fruit with two petals. L–M: Paepalanthus sessiliflorus var. sessiliflorus. L. open staminate flower showing calyx, anthophore, corolla, androecium and floral bract. M. open pistillate flower showing calyx, corolla, gynoecium and floral bract. N–P: Paepalanthus leucocephalus. N. open staminate flower showing calyx, anthophore, corolla, androecium and floral bract. O. closed pistillate flower showing calyx, corolla and floral bract apex. P. open pistillate flower showing calyx, corolla and gynoecium. Q–S: Paepalanthus scleranthus. Q. open staminate flower showing calyx, anthophore, corolla, androecium and floral bract. R. closed pistillate flower showing calyx, corolla and floral bract apex. S. open pistillate flower showing calyx, corolla and gynoecium [A–K. Queiroz 10917, holotype of P. paganuccii (HUEFS), L–M. Andrade 623 (HUEFS), N–P. Andrade 549 (HUEFS), Q–S. Alves 4015 (RB), drawings by AMG inked in by Carla Lima].