Nissolia stipulata I. Castro & Fort.-Perez

Silva, Isabella Cristina De Castro, Moura, Tânia Maria De, Gissi, Danilo Soares & Perez, Ana Paula Fortuna, 2021, A new species of Nissolia Jacq. (Leguminosae, Papilionoideae) from Northern Brazil, recording a new gland type for the genus, Phytotaxa 482 (1), pp. 80-86 : 82-83

Nissolia stipulata I. Castro & Fort.-Perez , sp. nov. ( Fig. 1 )

Nissolia stipulata is morphologically similar to N. bracteosa and N. brasiliensis ; differing mainly in the density of the secretory emergences in the calyx which vary in number from 124 and 158 (22 to 64 in N. bracteosa and 14 to 31 in N. brasiliensis ), solitary flowers and fasciculate inflorescences (vs. raceme in N. bracteosa ), the width of stipules 4–7 mm in N. stipulata (vs. 2–3 mm in N. bracteosa and 1–2 mm in N. brasiliensis ), and the width of bracts, 2–4 mm in N. stipulata (vs. 5–7 mm in N. bracteosa and 1–2 mm in N. brasiliensis ).

Type:— BRAZIL. Tocantins: Babaçulândia, estrada Babaçulândia – Filadélfia km 4 , área de influência indireta, 07º13’39”S, 47º46’00”O, 160m, 20 April 2018, fl. Fr., G. Pereira-Silva, G. A. Moreira, J. B. Pereira, J. P. do Amaral, 13147 (holotype CEN-00091319 ! , isotype BOTU-33722 ! ).

Woody, twining vine. Secretory emergences (glandular bristles) in the stipules, bracts, calyx and non-glandular trichomes densely covering the stem, stipules, bracts, calyx and outer surfaces of the standard petal. Stems sulcate. Stipules persistent, 6–8 × 4–7 mm, oval, margin serrate. Leaves 5-foliolate; petiole 3.9–5 cm long, sulcate; rachis 3.2– 3.9 cm long, glabrous to subglabrous adaxially, pubescent and with translucent punctuations abaxially; stipules absent; lateral leaflets 3.1–4 × 2.7–2.9 cm, obovate to elliptical, rounded at base, rounded, retuse or mucronate at apex, margin entire; terminal leaflet 3.5–4.7 × 2.4–3.4 cm, ovate to elliptic, rounded at base, rounded or mucronate at apex, margin entire. Inflorescence axillary, flowers solitary or fasciculate, 4–9 cm long. Bracts 7–9 × 2–4 mm, ovate. Pedicels 1.7–2.9 cm long. Calyx campanulate, 1.1–1.2 cm long; lobes 2–4 mm long, linear, number of secretory emergences: 124 –158. Corolla reported as yellow [G. Pereira-Silva et al. 1314 7 (BOTU, CEN)], 3–3.2 cm long. Standard ovate to elliptic, 2.9–3.2 × 1.6–1.9 cm, retuse at apex; claw 5–7 mm long; auricule absent. Wings elliptical, 2.6–2.9 × 0.6–0.7 cm, glabrous; claw 4–5 mm long; auricule 1–2 mm long. Keel petals elliptical, 2.6–2.9 × 0.5–0.6 cm, glabrous; claw 1–2 mm long; auricule 5 mm long. Androecium 10, 2.2–2.7 cm long, gamostemone, 80% fused, glabrous; anthers 1–2 mm long, basifixed. Gynoecium 2–2.4 cm long; ovary 9–11 mm long, pubescent, style pubescent, stigma minute, capitate. Fruit lomentum, cylindrical, sulcate, 15 × 0.3 cm, 11 auriculate, article 9 mm long, pubescent. Seeds not observed.

Distribution and habitat: — Nissolia stipulata was collected at an altitude of about 160 m, at the forest edge, in a highly disturbed environment. The area where the type specimen was collected (the only collection from which the species is known) was reported as riparian forest on clay soil. According to the collector G. Pereira-Silva (personal communication, April 23 rd 2020) this area is likely to be partly submerged during the rainy season. The distribution map was generated using ARCGIS software, using geographic coordinates extracted from locality data. So far, Nissolia stipulata is considered endemic to the Tocantins state ( Fig. 2 ); it is the first reported for the genus in this state.

Phenology: —The species was collected in April with flowers and immature fruits.

Etymology: — Nissolia stipulata was named due to the distinct morphology of its relatively larger stipules (when compared with the other taxa of the genus).

Conservation status: —As Nissolia stipulata is known by a single collection, following the IUCN (2019), we are assessing this species as Data Deficient (DD).

Taxonomic comments: —This new species is similar to Nissolia bracteosa and also can be confused with N. brasiliensis . However, these species differ mainly by the density of the secretory emergences in the calyx with number varying of 124 to 158 (22 to 64 in N. bracteosa and 14 to 31 in N. brasiliensis ), solitary flowers or fasciculate inflorescence (vs. raceme in N. bracteosa ), the width of the stipules 4–7 mm in N. stipulata (vs. 2–3 mm in N. bracteosa and 1–2 mm in N. brasiliensis ), and the width of bracts 2–4 mm in N. stipulata (vs. 5–7 mm in N. bracteosa and 1–2 mm in N. brasiliensis ). The three species can be differentiated by the characters listed in Table 1 .

Anatomy: —The bristles are in fact emergences with secretory potential. They are multiseriate and cylindrical with a conical apex ( Fig 3 ). They are coated by non-glandular trichomes and present stomata on the epidermis ( Fig 3c ). They are filled with parenchyma cells and possess a vascular bundle at the center ( Fig 3d ). The non-glandular trichomes are uniseriate, with a round flattened cell at the base, one or two rectangular cells and a conical upper portion consisting of a filiform cell ( Fig 3 c-d). Frequently referred to as glandular trichomes, emergences differ from trichomes due to their origin. Emergences are originated from the ground meristem while trichomes protrude uniquely from the protodermis ( Evert 2006). The presence of parenchyma, epidermis, stomata, xylem and non-glandular trichomes evidence that these bristles are in fact emergences. These structures are reported here for the first time for this genus, and are poorly known in Legumes, requiring further anatomic studies.

Figures

FIGURE 1. Nissolia stipulata. A. Habit. B. Detail of stipules. C. Leaf. D. Bracts. E. Flower. F. Detail of the calyx trichomes. G. Calyx opened out, inner surface. H. Dissected perianth showing standard above, in the centre. Wings to the sides and keel petals below. I. Androecium. J. Gynoecium. K. Detail of capitate stigma. Illustrated by Klei Souza.

FIGURE 2. Distribution map of Nissolia stipulata. Map plotted using ARCGIS software.

FIGURE 3. Secretory emergences fromNissolia stipulata calyx.a.Cross-section of the whole emergence showing non-glandular trichomes (NGT) covering the epidermis (Ep) and the parenchyma filling the emergence body. b. Detail from the emergence apex c. Diaphanized and stained emergence showing the NGT, stomata (St) and the vascular bundle (VB). d. Detail of the vascular bundle showing the helical vessel elements from the xylem (Xy) and non-glandular trichomes (NGT).