Anatomical and micromorphological study on some understudied taxa of Thlaspi L. s. lat. (Brassicaceae)

Abstract

This study investigates the seed and fruit anatomy and micromorphology of five pennycress taxa (Thlaspi L. sensu lato) from Turkey, some of which have not been previously investigated. Systematic work in this group suffers from a lack of comprehensive anatomical and micromorphological data, especially for narrowly endemic species. We find that seed surface structure is taxonomically more useful than seed coat anatomy in Thlaspi s. lat., but despite this, it remains understudied. Our results indicate that the most useful anatomical characters are seed-epidermis cell shape and the presence of mucilage cells. As for micromorphology, seed periclinal walls and cell shape were most significant. Thlaspi ceratocarpon Murray, the only taxa remaining in Thlaspi sensu stricto, was unique among these taxa both anatomically and micromorphologically. It notably differs from Thlaspi alliaceum L., according to our results, corroborating recent studies that placed the latter into Mummenhoffia Esmailbegi & Al-Shehbaz. Our PCoA analysis resulted in a close grou** of T. jaubertii Hedge, T. crassum P.H. Davis and T. cilicicum (Boiss) Hayek, three species that have been moved to Noccaea Moench, based on molecular evidence. We discuss the fragmentation of Thlaspi s. lat. into smaller genera in the context of broader trends in plant systematics.

Appendix

41304–3	T. cilicicum	1	elongated	1	isodiametric	7.56	1–2 layers	crushed	19.49	0	1	rectangular	19.37	± rounded	1	2	3–4 layers	dense	34.58	1–2 layers	25.25	parenchyma - sclerenchyma	1–2 layers	colliculate	wavy to undulate	thin	grooved	convex	smooth	elongated	irregular wrinkles	undulated	thin	grooved	convex	platelets	elongated
41305–1	T. cilicicum	1	elongated	1	elongated	3.73	1 layer	crushed	25.94	0	1	rounded	15.31	± rounded	0	2	3–4 layers	dense	42.31	1–2 layers	37.97	parenchyma - sclerenchyma	1–2 layers	colliculate	wavy to undulate	thin	grooved	convex	smooth	elongated	irregular wrinkles	undulated	thin	grooved	convex	platelets	elongated
41305–2	T. cilicicum	1	elongated	1	elongated	8.23	1 layer	crushed	22.29	0	1	rounded	14.75	± rounded	0	2	3–4 layers	dense	42.31	1–2 layers	37.97	parenchyma - sclerenchyma	1–2 layers	colliculate	wavy to undulate	thin	grooved	convex	smooth	elongated	irregular wrinkles	undulated	thin	grooved	convex	platelets	elongated
41305–3	T. cilicicum	1	elongated	1	elongated	7.81	1 layer	crushed	17.82	0	1	rounded	14.45	± rounded	1	2	2–3 layers	dense	42.15	1–2 layers	27.13	parenchyma - sclerenchyma	1–2 layers	colliculate	wavy to undulate	thin	grooved	convex	smooth	elongated	irregular wrinkles	undulated	thin	grooved	convex	platelets	elongated
41306–1	T. cilicicum	1	isodiametric	1	elongated	6.12	2–3 layers	crushed	18.59	0	1	elongated	16.59	± rounded	0	2	2–3 layers	dense	15.24	1–2 layers	20.99	parenchyma - sclerenchyma	1–2 layers	colliculate	wavy to undulate	thin	grooved	convex	smooth	elongated	irregular wrinkles	undulated	thin	grooved	convex	platelets	elongated
41306–2	T. cilicicum	1	elongated	1	isodiametric	6.28	2–3 layers	crushed	6.99	0	1	elongated	9.76	± rounded	0	2	1–2 layers	dense	14.1	1–2 layers	18.2	parenchyma - sclerenchyma	1–2 layers	colliculate	wavy to undulate	thin	grooved	convex	smooth	elongated	irregular wrinkles	undulated	thin	grooved	convex	platelets	elongated
41306–3	T. cilicicum	1	elongated	1	isodiametric	7.92	2–3 layers	crushed	12.21	0	1	elongated	13.57	± rounded	0	2	2–3 layers	dense	21.64	1–2 layers	20.29	parenchyma - sclerenchyma	1–2 layers	colliculate	wavy to undulate	thin	grooved	convex	smooth	elongated	irregular wrinkles	undulated	thin	grooved	convex	platelets	elongated
41291–0	T. crassum	1	elongated	1	isodiametric	10.61	1–2 layers	crushed	17.86	0	2	isodiametric	72.06	rectangular	1	2	3–4 layers	loose	86.83	1–2 layers	32.37	parenchyma - sclerenchyma	1–2 layers	colliculate	wavy	thin	grooved	convex	strongly verruculate	elongated	rugose	straight	thin	grooved	convex	platelets	elongated
41291–1	T. crassum	1	elongated	1	isodiametric	9.64	1–2 layers	crushed	15.14	0	1	isodiametric	38.36	rectangular	1	2	3–4 layers	loose	60.16	1 layer	27.26	parenchyma - sclerenchyma	1–2 layers	colliculate	wavy	thin	grooved	convex	strongly verruculate	elongated	rugose	straight	thin	grooved	convex	platelets	elongated
41291–2	T. crassum	1	elongated	1	isodiametric	8.56	1 layer	crushed	11.96	0	0	absent	0	rectangular	1	2	3–4 layers	loose	64.8	1–2 layers	26.55	parenchyma - sclerenchyma	1 layer	colliculate	wavy	thin	grooved	convex	strongly verruculate	elongated	rugose	straight	thin	grooved	convex	platelets	elongated
41291–3	T. crassum	1	elongated	1	isodiametric	7.29	1 layer	crushed	14.37	0	1	isodiametric	28.82	rectangular	1	2	3–4 layers	loose	44.62	1–2 layers	19.83	parenchyma - sclerenchyma	1 layer	colliculate	wavy	thin	grooved	convex	strongly verruculate	elongated	rugose	straight	thin	grooved	convex	platelets	elongated
41291–6	T. crassum	1	flat	1	isodiametric	8.09	1–2 layers	crushed	11.48	0	1	isodiametric	18.4	rectangular	0	2	2–3 layers	loose	70.34	1 layer	20.49	parenchyma - sclerenchyma	1 layer	colliculate	wavy	thin	grooved	convex	strongly verruculate	elongated	rugose	straight	thin	grooved	convex	platelets	elongated
41,291–7	T. crassum	1	flat	1	isodiametric	5.59	1–2 layers	crushed	19.78	0	1	isodiametric	29.93	rectangular	0	2	1–3 layers	loose	37.03	1–2 layers	26.68	parenchyma - sclerenchyma	1–2 layers	colliculate	wavy	thin	grooved	convex	strongly verruculate	elongated	rugose	straight	thin	grooved	convex	platelets	elongated
41292–0	T. jaubertii	1	flat	1	isodiametric	9.44	1–2 layers	crushed	12.93	1	1	isodiametric	46.22	rectangular	1	2	1–3 layers	dense	41.6	1–3 layers	27.14	parenchyma - sclerenchyma	1–2 layers	colliculate	wavy	thick	grooved	convex	verruculate	isodiametric	irregular wrinkles	straight	thin	grooved	convex	platelets	elongated
34461–1	T. jaubertii	1	flat	1	isodiametric	8.44	1–2 layers	crushed	11.23	1	1	isodiametric	19.52	rectangular	1	2	2–3 layers	dense	34.16	2–3 layers	61.6	parenchyma - sclerenchyma	1–2 layers	colliculate	wavy	thick	grooved	convex	verruculate	isodiametric	irregular wrinkles	straight	thin	grooved	convex	platelets	elongated
34461–3	T. jaubertii	1	flat	1	isodiametric	8.44	1–2 layers	crushed	11.23	1	1	isodiametric	19.52	rectangular	0	2	1–2 layers	dense	26.43	1–2 layers	49.79	parenchyma - sclerenchyma	1–2 layers	colliculate	wavy	thick	grooved	convex	verruculate	isodiametric	irregular wrinkles	straight	thin	grooved	convex	platelets	elongated
41293–1	T. jaubertii	1	flat	1	isodiametric	6.58	1–2 layers	crushed	18.88	1	1	isodiametric	18.59	rectangular	0	2	1–2 layers	dense	26.68	1–2 layers	42.41	parenchyma - sclerenchyma	1–2 layers	colliculate	wavy	thick	grooved	convex	verruculate	isodiametric	irregular wrinkles	straight	thin	grooved	convex	platelets	elongated
41293–2	T. jaubertii	1	flat	1	isodiametric	6.75	1–2 layers	crushed	17.67	1	1	isodiametric	29.5	rectangular	1	2	1–2 layers	dense	26.31	1–2 layers	26.05	parenchyma - sclerenchyma	1–2 layers	colliculate	wavy	thick	grooved	convex	verruculate	isodiametric	irregular wrinkles	straight	thin	grooved	convex	platelets	elongated