Cladrastis, Rafinesque, 1824

Na, Yuling, Blanchard, Jane & Wang, Hongshan, 2019, Fruits, seeds and flowers from the Puryear clay pit (middle Eocene Cockfield Formation), western Tennessee, USA, Palaeontologia Electronica (a 49) 23 (3), pp. 1-57 : 9-12

Genus CLADRASTIS Rafinesque, 1824 cf. Cladrastis sp.

Figure 12

1992 cf. Cladrastis sp. , Herendeen, p. 114, figs. 138–

141.

Description. “The fruits are 3.8+ cm long, 1.3–1.5 cm wide; apex obtuse to acute, base acute, stipitate; placental suture narrowly winged (1–2 mm), nonplacental suture sometimes attenuate; fruit margins with one to several shallow constrictions; ovules 1–2, oblique; seeds parallel to fruit margins; fruits thin, membranous, indehiscent” (Herendeen, 1992, p. 114).

Number of specimens examined. 4. UF15820- 005419, 005419’, 009012.

Remarks. Here we illustrate two of the four specimens reported from the Puryear clay pit by Herendeen (1992, p. 113, figures 138–141). He suggested that these fossils are similar to extant Cladrastis fruits in size and shape, narrow wing on the placental suture, parallel seeds, and membranous texture.

Leaves of Gleditsiophyllum eocenicum (Herendeen, 1992, figures 145–157), similar to several extant Asian rather than extant southeastern North American Cladrastis species (Herendeen, 1992, figures 158–165), are common in many Claiborne localities, including Bovay, Warman, and Puryear.

“Fruits similar to the Sophoreae ”

Figure 13

Description. “The fruits are 3.0– 3.5 cm long, 0.9– 1.7 cm wide; apex rounded, base abruptly rounded to truncated; margins straight to slightly constricted; fruits thin and membranous; ovules 3–4, oblique, asymmetrical; funiculus attached to seed subapically; seeds transverse; seed chambers not evident; sutures not prominent; narrow wing along placental suture.” (Herendeen, 1992, p. 123) Number of specimens examined. 3. UF15820- 000025a, 005847.

Remarks. Herendeen (1992, p. 123, figures 211– 221) reported eight specimens from the Claiborne Group from the Puryear locality and the Buchanan locality. The ovule outline and attachment are suggestive of their relationship with the Papilionoideae (Herendeen, 1992).

“Short, broad winged fruit”

Figure 14

Description. “The fruits are 3.0 – 6.0+ cm long, 1.6 – 3.2 cm wide; apex rounded to attenuate; base abruptly rounded to attenuate; fruits stipitate, 5 mm long; margins straight to slightly constricted; nonvascularized wing on placental suture, up to 2 mm wide; seeds 1–2, possibly round; valves thin and membranous, venous; orientation of major veins variable, from approximately perpendicular to oblique; calyx open, radially symmetrical.” (Herendeen, 1992, p. 129)

Number of specimens examined. 4. UF15820- 005834, 007679, 007082, 007696.

Remarks. Herendeen (1992, p. 129, figures 231– 238) reported eight specimens from the Bovay and Bolden clay pits, Mississippi, and the Puryear clay pit, Tennessee. Blanchard et al. (2016, p. 13, figure 10) re-illustrated two specimens from the Bovay and Bolden pits. Here we re-illustrate four specimens from the Puryear clay pit.

cf. Leguminosites ingafructoides Berry, 1930

Figure 15

1930 Leguminosites ingafructoides Berry , p. 87, pl.

13, fig. 8, pl. 29, fig. 1.

1992 cf. Leguminosites ingafructoides Berry, Herendeen , p. 133, figs. 244–245.

Description. “The fruit is 10.3 cm long, 3.1 cm wide; apex rounded, base obtuse; fruit stipitate, 5 mm long; margins with a single constriction; sutures thick, 2.4 mm; numerous parallel oblique striations; fruit dehiscent, valves twisting.”(Herendeen, 1992, p. 133)

Number of specimens examined. 1. UF15820- 005843.

Remarks. This is the specimen illustrated by Herendeen (1992, p. 133, figures 244–245). The thick suture of this fruit from Puryear is similar to the “Thick walled fruit” reported from the Warman clay pit, Tennessee (Herendeen, 1992, figures 239– 242; Wang et al., 2013, figure 14.4). They differ in that the Puryear fruit is larger, has oblique striations, a single constriction and no seed chambers.

Claiborne Fabaceae Fruit Type 1

Figures 16 , 17

Description. Compressed two-winged fruit, ca. 2.1 cm long and 2.5 cm wide (including wing); large wing ca. 6 mm wide, circumscribing two-thirds of the fruit body; reticulate veins forming at least three series of loops near the wing margin; small wing 3 mm wide, circumscribing one-third of the fruit body. Fruit body ca. 1.4 cm in diameter, covered with ca. 3 mm long spines. Pedicel ca. 23 mm long and 1 mm wide.

Number of specimens examined. 3. UF15820- 061134, 059396; CONN-R03-01.

Remarks. The venation pattern of the large wing of this fruit type is similar to that of Paleooreomunnea stoneana Dilcher, Potter and Crepet (Berry 1930, p. 60, pl. 46, figures 11, 12; Dilcher et al., 1976, p. 539, figures 26–32; Manchester, 1987, p. 59, figure 28E–L; Wang et al., 2013, p. 23–24, figure 19). However, they differ in that the wing of this fruit type is not lobed, lacks prominent major vein(s) and peltate scales, and the fruit body is covered with spines. The typical bilobed nut, tri-lobed wing, and persistent style and sepals of P. stoneana are not observed. Based on the length of the second wing of this fruit type, it seems that it only covers a very small portion of the nut, not as much as 2/3 of the nut as illustrated by Dilcher et al. (1976) and Manchester (1987) for P. stoneana .

The presence of two wings or a single discshaped wing and an indumentum on the nutlet are not uncommon in fossil and extant juglandaceous fruits. Nutlets of extant (e.g., Engelhardia serrata and Engelhardia spicata ; Lu et al., 1999) and fossil fruits such as Palaeocarya hispida Meng and Zhou (Meng et al., 2015) and Palaeocarya mississippiensis (Berry) Manchester (Manchester, 1987) are covered by trichomes/spines.

Similar winged fruits also occur in some extant members of Fabaceae , i.e., Pterocarpus and Riedeliella . Both genera were recently assigned to the monophyletic Pterocarpus clade within the Dalbergieae (Cardoso et al., 2013) . Pterocarpus is a pantropical genus with 72 accepted species (The Plant List; http://www.theplantlist.org). Some species, including Pterocarpus angolensis De Candolle , Pterocarpus echinatus Persoon , Pterocarpus erinaceus Poiret , and Pterocarpus indicus Willdenow have winged fruits with bristles on the fruit body and venation patterns similar to the Puryear specimens on the wing. Based upon these similarities, we tentatively assign these Puryear specimens to a fruit type in the Fabaceae .

Figures

FIGURE 12. cf. Cladrastis sp.: 1) UF15820-005419, fruit with two parallel seeds (s), narrow wing (w) along placental suture, and stipe (st); 2) Counterpart of UF15820-005419; 3) UF15820-009012, fruit showing narrow wing (w) along placental suture, obtuse apex, and style (stl) on the right. All scale bars equal 2 mm.

FIGURE 13. “Fruits similar to the Sophoreae” 1) UF15820-005847, fruit showing obtuse apex on the right and rounded base with stipe (s) on the left, and funiculus (f); 2) UF15820-000025a, fruit showing outlines of ovules (indicated by arrows), and rounded base with stipe on the right. All scale bars equal 2 mm.

FIGURE 14. “Short, broad winged fruit” 1) UF15820- 007696, fruit showing acuminate apex (a), wing (w) along placental suture, and valve venation (v); 2) UF15820-007679, fruit showing stipe (s), wing (w) along placental suture, and valve venation (v); 3) UF15820- 005834, fruit showing stipe (s) and wing (w) along placental suture; 4) UF15820-007082, fruit showing wing (w) along placental suture and valve venation (v). All scale bars equal 5 mm.

FIGURE 15. cf. Leguminosites ingafructoides Berry, 1930: UF15820-005843, fruit showing wide sutures (s), constriction (c) and vertical partition, and oblique striations (os) that are oriented parallel to the direction of the arrows. Scale bar equals 5 mm.

FIGURE 16. Claiborne Fabaceae Fruit Type 1: 1) UF15820-061134, showing nutlet in the middle, large wing at the top and small wing at the bottom. Arrows a and b indicate areas to be enlarged to show spines on the nutlet. The other two arrows on the right indicate that the two wings are on different levels with clay infilling between them. Scale bar equals 3 mm; 2) Enlargement of a in Figure 16.1 to show spines. Scale bar equals 1 mm; 3) Enlargement of b in Figure 16.1 to show spines going underneath the small wing. Scale bar equals 1 mm; 4) UF15820-059396, showing a pedicel (p) – or gynophore and spines (s). Scale bar equals 3 mm.

FIGURE 17. Claiborne Fabaceae Fruit Type 1: CONN- R03-01, compressed fruit showing a long pedicel and spines (indicated by arrow). Scale bar equals 3 mm.