Asterella sp

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tanay bose

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Mar 10, 2010, 11:38:11 AM3/10/10
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Plant Name: Asterella sp P. Beauv.

Family: Aytoniaceae

Date/Time- November 2008

Location- Place, Altitude, GPS- Panchmari Reserve Forest, Panchmari (Madhya Pradesh)

Habitat- Garden/ Urban/ Wild/ Type- Wild

Plant Habit- Tree/ Shrub/ Climber/ Herb- Herbaceous.

Height/Length- 2-4 cm (each thallus)

Plants in depressed interwoven patches or partial rosettes, simple or forked; branching primarily dichotomous or with intercalary branches, arising ventrally by narrow stipes, clavate, cordate or elongate; apical innovations occasional, forming cordate or elongate segments. 

 Thalli 20‑‑30 ´ 1.5‑‑6 mm, margins plane or ascending, often undulate, not crenulate; dorsal side green with purplish margins, underside purple; drying plant margins curling upward and inward exposing the purple underside, appearing as blackish‑purple tubes; dorsal epidermis not to very slightly areolate, firm, persistent; cell walls thin to moderately thick‑walled, trigones small or absent; oil cells scattered; air pores simple, the openings surrounded by 1‑‑3 tiers of 4‑‑8 scarcely differentiated cells; mid‑ventral thallus 8‑‑15 cells thick, of compact parenchymatous layers forming a broad keel gradually diminishing in thickness to the margins; dorsal spongy layers 2‑‑4 cells thick, containing air chambers lacking photosynthetic filaments; oil cells scattered; rhizoids dense, some smooth, some with internal pegs; ventral scales purple, in 2 rows, lunate to ovate with scattered oil cells; appendages hyaline, white or purplish, 1‑‑2(‑‑3) per scale, triangular to acuminate, not or scarcely constricted at base. 

Specialized asexual reproduction absent. 

Sexual condition  monoecious or dioecious; androecia sessile, often purplish, in dorsal patches of papillae or in discrete thickened pads surrounded by small subulate scales; the position of androecia in some monoecious species may vary from posterior to the gynoecial stalks (paroecious) to apical on dichotomous branches or short intercalary branches (autoecious) or antheridial papillae occasionally form a mid‑dorsal streak; gynoecia terminal on thalli; stalks 0.4‑‑5 cm with one rhizoid furrow, with or without hairlike scales at bases and/or apices; carpocephala bell‑shaped, domed, ovate or umbonate with air pores on upper surface, developing 1‑‑4 lobes below, each containing one sporophyte surrounded by an exerted, white to purplish, pleated conical pseudoperianth that splits into 8‑‑16 apically connate linear segments, becoming free with age in some species. 

 Sporophyte capsule spherical, irregularly circumscissile; spores areolate, the areolae bordered by partitions appearing in silhouette as a wing; elaters 120‑‑250 ´ 12‑‑15 µm, 1‑‑3 spiral.

Species ca. 80 (8 in the flora): on soil worldwide.



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Tanay Bose
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