Osmunda pulchella

Name

Osmunda pulchella

Rank

Species

Generic Name

[Genus] Osmunda

Authors (Pub.)

Bomfleur B. Grimm G. W. McLoughlin S.  

Publication

Osmunda pulchella sp. nov. from the Jurassic of Sweden — reconciling molecular and fossil evidence in the phylogeny of modern royal ferns (Osmundaceae) [2015/6]

Journal

BMC Evolutionary Biology

Volume

15

Issue

126

Page number

2

Year

2015

Fossil Status

rhizomata

Stratigraphy

Pliensbachian

Location

Korsaröd lake, near Höör, central Skåne, southern Sweden

Latitude/Longitude

55:58:54.6N

013:37:44.9E

Paleoregion

Eurasia (Europe)

Data for Holotypus

Repository

Naturhistoriska riksmuseet, Stockholm, Sweden

Repository Number

NRM S069649–S069655; S069656, S069657, S069658

Diagnosis

Rhizome creeping or semi-erect. Stem with ectophloicdictyoxylic siphonostele and two-layered cortex. Pith entirely parenchymatous. Xylem cylinder about 8–12 tracheids (mostly ca 0.4 mm) thick, dissected by narrow, complete, immediate leaf gaps, containing about twenty xylem segments in a given transverse section. Phloem and endodermis external only. Inner cortex ca 0.5–0.8 mm thick, homogeneous, parenchymatous, containing about ten leaf traces in a given transverse section; outer cortex ca 1.5–2.5 mm thick, homogeneous, sclerenchymatous, containing about 20 leaf traces in a given transverse section. Leaf traces in stem oblong, more or less reniform, adaxially concave, endarch with a single protoxylem strand at the point of emergence from stele, diverging at acute angles of ca 20–40°; protoxylem strand bifurcating only in outermost cortex or upon departure from stem. Petiole bases with adaxially concave vascular strand, one adaxial sclerenchyma band in vascular-strand concavity, parenchymatic cortex, a heterogeneous sclerenchyma ring, and an opposite pair of petiolar wings; adaxial sclerenchyma in inner cortex of petiole appearing in the form of a single patch or arch lining the vascular-bundle concavity with homogeneous thickness, differentiating distally into two thickened lateral masses connected by a thin strip, extending proximally only to base of petiole, not into stem; sclerenchyma ring of petiole base thicker than vascular bundle, heterogeneous, with a crescentic abaxial cap of thicker-walled fibres in the basal petiole portion differentiating distally into two lateral masses and ultimately into two lateral and one abaxial mass; petiolar wings in distal portions containing an elongate strip of thick-walled fibres. Roots diarch, usually arising singly from one leaf trace, containing scattered sclerenchyma fibres.