USGS 11600.23

  MA101

USNM Number

406634

See also:

USGS 11600.26 (USNM 406635), and USGS 11600.29 (USNM 406636)

 

Locality

Latitude: 56.268889° N

Longitude: -158.659722° W

Chignik (B-2) Quad.
Collected by R.A. Spicer and J.A. Wolfe.
Floodpain swamp.  Lower part of Tolstoi Formation.

Locality Map

Geology

 

Description

Leaf:  simple; symmetrical; wide obovate; bilobed; apex emarginate, apices of lobes acute; base acute or decurrent; margin entire; venation camptodromous; primary midvein moderate, straight; secondary veins arising at an acute angle (approximately 45°), more or less straight, sometimes branched abmedially, most apical secondaries very weak, parallel to margin; lobes served by two secondary veins, one running to lobe apex, apical secondary branched admedially, branches festooned brochidodromous, basal secondary branched abmedially, branches brochidodromous; tertiary veins mostly percurrent, sometimes branched one or more times, more or less straight, sometimes convex; ultimate marginal venation looped. 

 

Remarks

We have not been able to find any previously published descriptions of leaves such as these.  They are unusual in that the lobes have pointed, almost attenuate apices and are served not by a single medial vein but by a pair of secondaries.  The pinnate venation, festooned brochidodromous secondary veins, irregularly transverse tertiary venation, and entire margins are all features commonly found within the Magnoliidae.