Monographs Details: Archilejeunea porelloides subsp. chocoensis Gradst.
Authority: Gradstein, S. Robbert. 1994. Lejeuneaceae: Ptychantheae, Brachiolejeuneae. Fl. Neotrop. Monogr. 62: 216. (Published by NYBG Press)
Synonyms:Marchesinia longistipula Steph.
Description:Subspecies Description - Dioicous. Plants up to 5 cm long × 3 mm wide, glossy yellow brown, ascending to erect, standing away from the substrate. Stems in cross section composed of 20-25 epidermal cells surrounding 28-35 similar medullary cells; ventral merophyte 6-8 cell rows wide. Leaves subimbricate, dorsal lobe oblong, ca. 1.1-1.3 × 0.6-0.7 mm, sometimes falcate, apex rounded, margins plane, ventral margin gradually curved, forming a wide angle with the keel, not auriculate at keel junction; cells as in ssp. porelloides. Lobules subrectangular, 1/5-1/3 × lobe length, rather flat and with a discrete, 1-5 cells long tooth, the tooth 1-3 cells wide at the base, the uniseriate tip 1-2 cells long, apical margin truncate, angle between apical margin and ventral leaf margin at junction more than 90°, distal end of the free margin acute or connate with the lobe surface across 1-2 cells. Underleaves imbricate, concave, orbicular-obtrapezioid to transversely ovate, rarely longer than wide, 3.5-5 × stem width, apex truncate, plane or slightly recurved, margins not undulate, bases decurrent, insertion line arched. Gametoecia as in subsp, porelloides. Sporophyte not observed.

Discussion:Archilejeunea porelloides subspecies chocoensis is habitually similar to subsp. porelloides but the plants are usually somewhat more slender, the leaves are slightly smaller and more falcate, the lobules are smaller (often less than 1/3 × lobe length) and the underleaves are usually not elongated. An unusual morphological trait of subsp. chocoensis is the fact that in some lobules the distal end of the free margin is truncate and connate with the surface of the leaf lobe across 1-2 cells. I have never observed this feature in other species of Archilejeunea but in Lopholejeunea this is an excellent species character, e.g., of Lopholejeunea subfusca.

The most significant morphological character of subspecies chocoensis is the presence of a discrete lobule tooth, a feature which lacks in the typical populations of A. porelloides from inner Amazonia. However, in a specimen of A. porelloides from Ecuador, described by Stephani as Marchesinia longistipula Steph., lobules with or without teeth are present. Since the majority of the lobules were clearly toothed, I have identified this material as A. porelloides subsp. chocoensis. The Ecuadorian specimen shows that the two subspecies are very closely related and that morphologically intermediate populations may occur. The two subspecies of A. porelloides are of considerable biogeographic interest and illustrate a case of vicariant speciation on either side of the Andes.
Distribution:Panama Central America| Veraguas Panama Central America| Colombia South America| Chocó Colombia South America| Meta Colombia South America| Ecuador South America|