ESSEX   BOTANY   AND   MYCOLOGY  GROUPS 

This genus of Hornworts differs from Anthoceros in the absence of lacunae in the thallus, the presence of radiating lamellae on the upper surface, the smaller sporophytes and the yellow as opposed to black spores. The British material has now been assigned to two species, formerly only regarded as subspecies. They differ primarily in that P. laevis is dioicous and P. carolinianus monoicous. They are also spatially and temporally separated, P. carolinianus being a rare southern summer annual, whereas P. laevis is found throughout Britain and although usually annual it can be perennial in suitable sites and can also perennate by producing tubers.  Tubers have not been recorded in P. carolinianus. Small differences in spore ornimentation have been detected by electron microscopy on the type specimens, but A.J.E.Smith urges caution until more specimens have been examined. The only verified record of the existing Essex records would appear to be that of Edward Foster, from the Common Field, nr Walthamstow Church, c.1830 which was determined as subsp. carolinianus by Proskauer in 1954. A further specimen from Mark House Field, Walthamstow, also collected by Edward Forster, has not been traced. A specimen collected by Eric Saunders from Littlebury gravel and sand pits in 1959 as possible P. laevis was determined by Jean Paton as Aneura pinguis. His specimen  from a gravel pit in Thanet Sands near the A13 road in Grays in 1959 however is the confirmed voucher specimen for Vc18.. 

 Phaeoceros laevis (L.) Prosk.

Phaeoceros carolinianus (Michx.) Prosk