Liagora pedicellata M.Howe
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Authority
Britton, Nathaniel L. & Millspaugh, Charles F. 1920. The Bahama Flora.
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Family
Liagoraceae
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Scientific Name
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Description
Species Description - Thallus usually very soft and flaccid, 4-16 cm. long or high, irregularly monopodial, the main divisions paniculate or pyramido-paniculate, each branch surrounded in the living state by a soft mucous sheath about as thick as the whole diameter of the enclosed branch, this sheath showing a flocculent precipitate of microscopic calcareous granules arranged mostly in the walls of irregular alveolae, making surface in dried state minutely alveolate or farinaceousalveolate; branches for the most part progressively shorter, varying from rather sparse to crowded, tapering slightly to obtuse or subacute apex, 1.2-2 mm. broad towards apex, including more or less calcified mucous sheath, 0.450.8 mm. without sheath; central axis in basal parts 1.5-2.5 mm. in diameter, more or less calcified and often denudate, in ultimate branches mostly 150-175 µ in diameter, usually readily visible after decalcification, commonly reduced to about four filaments towards apex, the cells subeylindric-ellipsoid or dolioform, 104- 340 µ X 36-104 µ, descending rhizoids 8-13 µ in diameter few in younger parts; fascicles of assimilatory filaments mostly 300-600 µ long, 4-7 times divided, usually subtrichotomous at one or two of the proximal articulations, otherwise dichotomous, intermingled in older parts with simple or subsimple filaments 8-11 cells long, all filaments submoniliate in distal parts, the distal or subdistal cells mostly obovoid, 15-26 µ long, 12-16 (20) µ broad; apical hairs numerous, slender, long and flexuous, often cylindric-capitate, soon gelatinizing, leaving inconspicuous vestigia; monoicous; antheridia in small inconspicuous tufts mostly 13-20 µ broad, on ultimate and penultimate segments; carpogonial branch straight, 20-25 µ broad, of 4-6 cells (including the usually long pedicel cell) situated terminally or subterminally on the third or fourth segment of the fascicle; cystocarp compact, subhemispheric, 90-215 µ broad, peripheral, terminating a rather stout and rigid submonopodial axis or pedicel 300-450 µ (4-8 cells) long, involucre wanting or represented by a few short appresseddeeurrent or pendent rhizoidal filaments; carpospores obovoid, ellipsoid, or pyriform, 23-39 µ X 15-21 µ.
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Discussion
On more or less exposed rocks, near the low-water mark (also found washed ashore), Cockburn Harbor, South Caicos (Howe 555J, type), Malcolm Road, South Caicos, Atwood Cay, Mariguana, Rose Island, Whale Cay, Great Bahama : Florida (Boot Key).
Liagora pedicellata is allied to L. pinnata Harv., in general habit, but differs constantly in being more flaccid and mucous, in the more external or sheathing (usually lighter) calcification, in the smaller simpler more terminal tufts of antheridia, in the straighter, more terminal carpogonial branches, in the more peripheral, more obviously pedicelled, more compact and homogeneous, large-spored cystocarps, which are destitute of a proper ascending involucre. In L. pedicellata, the calcification is mostly in the external mucous sheath, extending irregularly down among the peripheral filaments in the older parts : the distal ends of the filaments are covered by it with the possible exception of the tips of the hairs in the apical region. In L. pinnata the calcification is in among the filaments, the distal ends of most of the filaments, with or without hairs, remaining free or protruding beyond the calcification. The essentially terminal rather than lateral carpogonial branches might be regarded by some as sufficient ground for placing the plant in the genus Trichogloea rather than in Liagora, but in habit and other characters the plant is essentially a Liagora, bearing, in fact, so close a resemblance to L. mucosa that a microscopic examination is commonly necessary for their separation.
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Distribution
Cockburn Harbor, South Caicos (Howe 555J, type), Malcolm Road, South Caicos, Atwood Cay, Mariguana, Rose Island, Whale Cay, Great Bahama : Florida
Turks and Caicos Islands South America| Grand Bahama Bahamas South America| Florida United States of America North America|