diff --git a/init.lua b/init.lua
index 9859925..7fa9387 100644
--- a/init.lua
+++ b/init.lua
@@ -24,7 +24,7 @@ local LEAVES_NARROWRADIUS = 3 -- For narrow typed conifers.
 local CONIFERS_DISTANCE = 4
 local CONIFERS_ALTITUDE = 30
 
-local REMOVE_TREES = false -- Remove trees above CONIFERS_ALTITUDE?
+local REMOVE_TREES = false -- Remove trees above CONIFERS_ALTITUDE? It kills default trees from the top.
 
 local SAPLING_CHANCE = 100 -- 1/x chances to grow a sapling.
 
@@ -176,6 +176,15 @@ minetest.register_node("conifers:sapling", {
 })
 
 
+conifers_c_air = minetest.get_content_id("air")
+conifers_c_tree = minetest.get_content_id("default:tree")
+conifers_c_leaves = minetest.get_content_id("default:leaves")
+conifers_c_dirt_with_grass = minetest.get_content_id("default:dirt_with_grass")
+
+conifers_c_con_trunk = minetest.get_content_id("conifers:trunk")
+conifers_c_con_leaves = minetest.get_content_id("conifers:leaves")
+conifers_c_con_leaves_special = minetest.get_content_id("conifers:leaves_special")
+
 
 --
 -- Craft definitions
@@ -322,16 +331,12 @@ function conifers:are_leaves_surrounded(pos)
 	--
 	-- Check if a leaves block does not interfer with something else than the air or another leaves block.
 	--
-	local replacable_nodes = {
-		"air", 
-		"conifers:leaves", 
-		"conifers:leaves_special"
-	}
+	local replacable_nodes = {conifers_c_air, conifers_c_con_leaves, conifers_c_con_leaves_special}
 
 	-- Let's check if the neighboring node is a replacable node.
 	for i = -1,1,2 do
-		if not (conifers:table_contains(replacable_nodes, minetest.get_node({x=pos.x+i, y=pos.y, z=pos.z}).name)
-			or conifers:table_contains(replacable_nodes, minetest.get_node({x=pos.x, y=pos.y, z=pos.z+i}).name)
+		if not (conifers:table_contains(replacable_nodes, nodes[area:index(pos.x+i, pos.y, pos.z)])
+			or conifers:table_contains(replacable_nodes, nodes[area:index(pos.x, pos.y, pos.z+i)])
 		) then
 			return true
 		end
@@ -351,14 +356,26 @@ end
 function conifers:add_leaves_block(pos, special, near_trunk)
 	if (not conifers:are_leaves_surrounded(pos))
 	or near_trunk then
+		local p_pos = area:index(pos.x, pos.y, pos.z)
 		if special == 0 then
-			minetest.add_node(pos , { name = "conifers:leaves" })
+			nodes[p_pos] = conifers_c_con_leaves
 		else
-			minetest.add_node(pos , { name = "conifers:leaves_special" })
+			nodes[p_pos] = conifers_c_con_leaves_special
 		end
 	end
 end
 
+-- Put a small circle of leaves around the trunk.
+--    [ ]
+-- [ ][#][ ]
+--    [ ]
+function conifers:add_small_leaves_circle(c, special)
+	for i = -1,1,2 do
+		conifers:add_leaves_block({x=c.x+i, y=c.y, z=c.z}, special, true)
+		conifers:add_leaves_block({x=c.x, y=c.y, z=c.z+i}, special, true)
+	end
+end
+
 --
 -- make_leaves(middle point, min radius, max radius, type of leaves)
 --
@@ -368,6 +385,10 @@ end
 --	1: bright leaves (special)
 --
 function conifers:make_leaves(c, radius_min, radius_max, special)
+	if radius_max <= 1 then
+		conifers:add_small_leaves_circle(c, special)
+		return
+	end
 	--
 	-- Using the midpoint circle algorithm from Bresenham we can trace a circle of leaves.
 	--
@@ -376,42 +397,26 @@ function conifers:make_leaves(c, radius_min, radius_max, special)
 		local m_z = r
 		local m_m = 5 - 4 * r		
 		while m_x <= m_z do
-			if radius_max > 1 then
-				if r == 1 then
-					-- Add a square of leaves (fixing holes near the trunk).
-					-- [ ]   [ ]
-					--    [#]
-					-- [ ]   [ ]
-					conifers:add_leaves_block({x = -1 + c.x, 	y = c.y, z = 1 + c.z}, special)
-					conifers:add_leaves_block({x = 1 + c.x, 	y = c.y, z = 1 + c.z}, special)
-					conifers:add_leaves_block({x = -1 + c.x, 	y = c.y, z = -1 + c.z}, special)
-					conifers:add_leaves_block({x = 1 + c.x, 	y = c.y, z = -1 + c.z}, special)
-	 				--    [ ]
-					-- [ ][#][ ]
-					--    [ ]
-					conifers:add_leaves_block({x = c.x, 		y = c.y, z = -1 + c.z}, special, true)
-					conifers:add_leaves_block({x = c.x, 		y = c.y, z = 1 + c.z}, special, true)
-					conifers:add_leaves_block({x = -1 + c.x, 	y = c.y, z = c.z}, special, true)
-					conifers:add_leaves_block({x = 1 + c.x, 	y = c.y, z = c.z}, special, true)
-				else
-					conifers:add_leaves_block({x = m_x + c.x, 	y = c.y, z = m_z + c.z}, special)
-					conifers:add_leaves_block({x = m_z + c.x, 	y = c.y, z = m_x + c.z}, special)
-					conifers:add_leaves_block({x = -m_x + c.x, 	y = c.y, z = m_z + c.z}, special)
-					conifers:add_leaves_block({x = -m_z + c.x, 	y = c.y, z = m_x + c.z}, special)
-					conifers:add_leaves_block({x = m_x + c.x, 	y = c.y, z = -m_z + c.z}, special)
-					conifers:add_leaves_block({x = m_z + c.x, 	y = c.y, z = -m_x + c.z}, special)
-					conifers:add_leaves_block({x = -m_x + c.x, 	y = c.y, z = -m_z + c.z}, special)
-					conifers:add_leaves_block({x = -m_z + c.x, 	y = c.y, z = -m_x + c.z}, special)	
+			if r == 1 then
+				-- Add a square of leaves (fixing holes near the trunk).
+				-- [ ]   [ ]
+				--    [#]
+				-- [ ]   [ ]
+				for i = 1,-1,-2 do
+					for j = -1,1,2 do
+						conifers:add_leaves_block({x=c.x+j, y=c.y, z=c.z+i}, special)
+					end
 				end
+
+				conifers:add_small_leaves_circle(c, special)
 			else
-				-- Put a small circle of leaves around the trunk.
- 				--    [ ]
-				-- [ ][#][ ]
-				--    [ ]
-				conifers:add_leaves_block({x = c.x, 		y = c.y, z = -1 + c.z}, special, true)
-				conifers:add_leaves_block({x = c.x, 		y = c.y, z = 1 + c.z}, special, true)
-				conifers:add_leaves_block({x = -1 + c.x, 	y = c.y, z = c.z}, special, true)
-				conifers:add_leaves_block({x = 1 + c.x, 	y = c.y, z = c.z}, special, true)
+				for i = -1,1,2 do
+					for j = -1,1,2 do
+						for _,a in ipairs({{m_x, m_z}, {m_z, m_x}}) do
+							conifers:add_leaves_block({x=j*a[1]+c.x, y=c.y, z=i*a[2]+c.z}, special)
+						end
+					end
+				end
 			end
 			-- Stuff...
 			if m_m > 0 then
@@ -433,11 +438,24 @@ end
 --	1: narrow pine
 --
 function conifers:make_conifer(pos, conifer_type)
+	local height = math.random(TRUNK_MINHEIGHT, TRUNK_MAXHEIGHT) -- Random height of the conifer.
+
+	local t1 = os.clock()
+	local manip = minetest.get_voxel_manip()
+	local vwidth = LEAVES_MAXRADIUS+1
+	local emerged_pos1, emerged_pos2 = manip:read_from_map({x=pos.x-vwidth, y=pos.y, z=pos.z-vwidth},
+		{x=pos.x+vwidth, y=pos.y+height+1, z=pos.z+vwidth})
+
+	area = VoxelArea:new({MinEdge=emerged_pos1, MaxEdge=emerged_pos2})
+	nodes = manip:get_data()
+
 	-- Check if we can gros a conifer at this place.
-	local node = minetest.get_node(pos).name
-	if minetest.get_node({x=pos.x, y=pos.y-1, z=pos.z}).name ~= "default:dirt_with_grass"
-	and (node ~= "air"
-		or node ~= "conifers:sapling"
+	local p_pos = area:index(pos.x, pos.y, pos.z)
+	local d_p_pos = nodes[p_pos]
+
+	if nodes[area:index(pos.x, pos.y-1, pos.z)] ~= conifers_c_dirt_with_grass
+	and (d_p_pos ~= conifers_c_air
+		or d_p_pos ~= conifers_c_con_sapling
 	) then
 		return false
 	--else
@@ -445,21 +463,17 @@ function conifers:make_conifer(pos, conifer_type)
 			--minetest.add_node(pos , {name = "air"})
 		--end
 	end
-	
-	local height = math.random(TRUNK_MINHEIGHT, TRUNK_MAXHEIGHT) -- Random height of the conifer.
 
 	-- Let's check if we can grow a tree here.
 	-- That means, we must have a column of 'height' high which contains
 	-- only air.
 	for j = 1, height - 1 do -- Start from 1 so we can grow a sapling.
-		if minetest.get_node({x=pos.x, y=pos.y+j, z=pos.z}).name ~= "air" then
+		if nodes[area:index(pos.x, pos.y+j, pos.z)] ~= conifers_c_air then
 			-- Abort
 			return false
 		end
 	end
 
-	local t1 = os.clock()
-
 	local leaves_height = math.random(LEAVES_MINHEIGHT, LEAVES_MAXHEIGHT) -- Level from where the leaves grow.
 	local current_block = {} -- Duh...
 	local leaves_radius = 1
@@ -470,7 +484,7 @@ function conifers:make_conifer(pos, conifer_type)
 	for i = 0, height - 1 do
 		current_block = {x=pos.x, y=pos.y+i, z=pos.z}
 		-- Put a trunk block.
-		minetest.add_node(current_block , {name = "conifers:trunk"})
+		nodes[area:index(pos.x, pos.y+i, pos.z)] = conifers_c_con_trunk
 		-- Put some leaves.
 		if i >= leaves_height then
 			-- Put some leaves.
@@ -484,10 +498,9 @@ function conifers:make_conifer(pos, conifer_type)
 				-- Check if the current radius is the maximum radius at this level.
 				if leaves_radius > leaves_max_radius then
 					leaves_radius = 1
-					leaves_max_radius = leaves_max_radius+1
 					-- Does it exceeds the maximum radius?
-					if leaves_max_radius > LEAVES_MAXRADIUS then
-						leaves_max_radius = LEAVES_MAXRADIUS
+					if leaves_max_radius < LEAVES_MAXRADIUS then
+						leaves_max_radius = leaves_max_radius+1
 					end
 				end
 			else -- Narrow type
@@ -504,7 +517,15 @@ function conifers:make_conifer(pos, conifer_type)
 	current_block.y = current_block.y+1
 	conifers:add_leaves_block(current_block, special)
 
-	-- Blahblahblah
-	print (string.format('[conifers] A conifer has grown at ('..pos.x..','..pos.y..','..pos.z..') with a height of '..height..' after ca. %.2fs', os.clock() - t1))
+	manip:set_data(nodes)
+	manip:write_to_map()
+	print (string.format('[conifers] A conifer has grown at '..
+		'('..pos.x..','..pos.y..','..pos.z..')'..
+		' with a height of '..height..
+		' after ca. %.2fs', os.clock() - t1)
+	)	-- Blahblahblah
+	local t1 = os.clock()
+	manip:update_map()
+	print (string.format('[conifers] map updated after ca. %.2fs', os.clock() - t1))
 	return true
 end
diff --git a/init_old.lua b/init_old.lua
new file mode 100644
index 0000000..9859925
--- /dev/null
+++ b/init_old.lua
@@ -0,0 +1,510 @@
+--------------------------------------------------------------------------------
+--
+-- CONIFERS MOD
+-- For Minetest
+-- Created by Cisoun (cysoun[at]gmail.com).
+--
+-- This mod adds some conifers randomly at a certain altitude.
+-- There are two types of conifers: regular and narrow.
+-- You can define the altitude at which they spawn and their structure and
+-- choose if you want to keep normal trees above this altitude.
+--
+--------------------------------------------------------------------------------
+
+-- Structure definitions.
+
+local TRUNK_MINHEIGHT = 7
+local TRUNK_MAXHEIGHT = 25
+
+local LEAVES_MINHEIGHT = 2
+local LEAVES_MAXHEIGHT = 6
+local LEAVES_MAXRADIUS = 5
+local LEAVES_NARROWRADIUS = 3 -- For narrow typed conifers.
+
+local CONIFERS_DISTANCE = 4
+local CONIFERS_ALTITUDE = 30
+
+local REMOVE_TREES = false -- Remove trees above CONIFERS_ALTITUDE?
+
+local SAPLING_CHANCE = 100 -- 1/x chances to grow a sapling.
+
+local INTERVAL = 3600
+
+-- End of structure definitions.
+
+
+
+conifers = {}
+
+
+
+--------------------------------------------------------------------------------
+--
+-- Definitions
+--
+--------------------------------------------------------------------------------
+
+--
+-- Node definitions
+--
+minetest.register_node("conifers:trunk", {
+	description = "Conifer trunk",
+	tile_images = { 
+		"conifers_trunktop.png", 
+		"conifers_trunktop.png", 
+		"conifers_trunk.png", 
+	},
+	--inventory_image = minetest.inventorycube(
+		--"conifers_trunktop.png", 
+		--"conifers_trunk.png", 
+		--"conifers_trunk.png"
+	--),
+	paramtype = "facedir_simple",
+	material = minetest.digprop_woodlike(1.0),
+	groups = {
+		tree = 1,
+		snappy = 2,
+		choppy = 2,
+		oddly_breakable_by_hand = 1,
+		flammable = 2
+	},
+	sounds = default.node_sound_wood_defaults()
+})
+
+local tex_reversed_trunk = "conifers_trunk.png^[transformR90"
+minetest.register_node("conifers:trunk_reversed", {
+	description = "Conifer reversed trunk",
+	tile_images = { 
+		tex_reversed_trunk, 
+		tex_reversed_trunk,
+		"conifers_trunktop.png", 
+		"conifers_trunktop.png", 
+		tex_reversed_trunk, 
+	},
+	--inventory_image = minetest.inventorycube(
+		--"conifers_trunk.png",
+		--"conifers_trunktop.png",
+		--"conifers_trunk.png"
+	--),
+	paramtype = "facedir_simple",
+	material = minetest.digprop_woodlike(1.0),
+	legacy_facedir_simple = true,
+	groups = {
+		tree = 1,
+		snappy = 2,
+		choppy = 2,
+		oddly_breakable_by_hand = 1,
+		flammable = 2
+	},
+	sounds = default.node_sound_wood_defaults()
+})
+
+minetest.register_node("conifers:leaves", {
+	description = "Conifer leaves",
+	drawtype = "allfaces_optional",
+	visual_scale = 1.3,
+	tile_images = { "conifers_leaves.png" },
+	--inventory_image = "conifers_leaves.png",
+	paramtype = "light",
+	groups = {
+		snappy = 3,
+		--leafdecay = 3,
+		flammable = 2
+	},
+	drop = {
+		max_items = 1,
+		items = {
+			{
+				-- player will get sapling with 1/20 chance
+				items = {'conifers:sapling'},
+				rarity = 20,
+			},
+			{
+				-- player will get leaves only if he get no saplings,
+				-- this is because max_items is 1
+				items = {'conifers:leaves'},
+			}
+		}
+	},
+	sounds = default.node_sound_leaves_defaults()
+})
+
+minetest.register_node("conifers:leaves_special", {
+	description = "Bright conifer leaves",
+	drawtype = "allfaces_optional",
+	visual_scale = 1.3,
+	tile_images = { "conifers_leaves_special.png" },
+	--inventory_image = "conifers_leaves_special.png",
+	paramtype = "light",
+	groups = {
+		snappy = 3,
+		--leafdecay = 3,
+		flammable = 2
+	},
+	drop = {
+		max_items = 1,
+		items = {
+			{
+				-- player will get sapling with 1/20 chance
+				items = {'conifers:sapling'},
+				rarity = 20,
+			},
+			{
+				-- player will get leaves only if he get no saplings,
+				-- this is because max_items is 1
+				items = {'conifers:leaves'},
+			}
+		}
+	},
+	sounds = default.node_sound_leaves_defaults()
+})
+
+minetest.register_node("conifers:sapling", {
+	description = "Conifer sapling",
+	drawtype = "plantlike",
+	tile_images = {"conifers_sapling.png"},
+	inventory_image = "conifers_sapling.png",
+	wield_image = "conifers_sapling.png",
+	paramtype = "light",
+	walkable = false,
+	groups = {
+		snappy = 2,
+		dig_immediate = 3,
+		flammable = 2
+	},
+	sounds = default.node_sound_defaults(),
+})
+
+
+
+--
+-- Craft definitions
+--
+minetest.register_craft({
+	output = "conifers:trunk_reversed 2",
+	recipe = {
+		{"conifers:trunk", "conifers:trunk"},
+	}
+})
+
+minetest.register_craft({
+	output = "conifers:trunk 2",
+	recipe = {
+		{"conifers:trunk_reversed"},
+		{"conifers:trunk_reversed"}
+	}
+})
+
+minetest.register_craft({
+	output = 'default:wood 4',
+	recipe = {
+		{'conifers:trunk'}
+	}
+})
+
+minetest.register_craft({
+	output = 'default:wood 4',
+	recipe = {
+		{'conifers:trunk_reversed'}
+	}
+})
+
+
+--
+-- ABM definitions
+--
+-- Spawn random conifers.
+minetest.register_abm({
+	nodenames = "default:dirt_with_grass",
+	interval = INTERVAL,
+	chance = 200.2,
+	
+	action = function(pos, node)
+		local p = {x=pos.x, y=pos.y+1, z=pos.z}
+   		if minetest.get_node(p).name == "air"
+   		and pos.y >= CONIFERS_ALTITUDE
+   		and (not conifers:is_node_in_cube({"conifers:trunk"}, pos, CONIFERS_DISTANCE)) then
+   			conifers:make_conifer(p, math.random(0, 1))
+		end
+    end
+})
+
+-- Saplings.
+minetest.register_abm({
+	nodenames = "conifers:sapling",
+	interval = INTERVAL,
+	chance = SAPLING_CHANCE,
+	
+	action = function(pos, node)
+   		if minetest.get_node({x=pos.x, y=pos.y+1, z=pos.z}).name == "air" then
+   			conifers:make_conifer(pos, math.random(0, 1))
+   		end
+    end
+})
+
+-- Should we remove all the trees above the conifers altitude?
+if REMOVE_TREES == true then
+	minetest.register_abm({
+		nodenames = {
+			"default:tree", 
+			"default:leaves"
+		},
+		interval = INTERVAL/100,
+		chance = 1,
+		
+		action = function(pos, node)
+			if minetest.get_node({x=pos.x, y=pos.y+1, z=pos.z}).name == "air"
+			and pos.y >= CONIFERS_ALTITUDE then
+				minetest.add_node(pos , {name = "air"})
+			end
+		end
+	})
+end
+
+
+
+--------------------------------------------------------------------------------
+--
+-- Functions
+--
+--------------------------------------------------------------------------------
+
+--
+-- table_contains(t, v)
+--
+-- Taken from the Flowers mod by erlehmann.
+--
+function conifers:table_contains(t, v)
+    for _,i in ipairs(t) do
+		if i == v then
+			return true
+		end
+    end
+    return false
+end
+
+--
+-- is_node_in_cube(nodenames, node_pos, radius)
+--
+-- Taken from the Flowers mod by erlehmann.
+--
+function conifers:is_node_in_cube(nodenames, pos, size)
+	local hs = math.floor(size / 2)
+    for x = pos.x-size, pos.x+size do
+		for y = pos.y-hs, pos.y+hs do
+			for z = pos.z-size, pos.z+size do
+				n = minetest.get_node_or_nil({x=x, y=y, z=z})
+				if n == nil
+				or n.name == 'ignore'
+				or conifers:table_contains(nodenames, n.name) then
+					return true
+				end
+			end
+		end
+    end
+    return false
+end
+
+--
+-- are_leaves_surrounded(position)
+--
+-- Return a boolean value set to 'true' if a leaves block is surrounded
+-- by something else than
+--  - air
+--  - leaves
+--  - special leaves
+--
+-- If a leaves block is surrounded by the blocks above, 
+-- it can be placed.
+-- Otherwise, it will replace blocks we want to keep.
+--
+function conifers:are_leaves_surrounded(pos)
+	--
+	-- Check if a leaves block does not interfer with something else than the air or another leaves block.
+	--
+	local replacable_nodes = {
+		"air", 
+		"conifers:leaves", 
+		"conifers:leaves_special"
+	}
+
+	-- Let's check if the neighboring node is a replacable node.
+	for i = -1,1,2 do
+		if not (conifers:table_contains(replacable_nodes, minetest.get_node({x=pos.x+i, y=pos.y, z=pos.z}).name)
+			or conifers:table_contains(replacable_nodes, minetest.get_node({x=pos.x, y=pos.y, z=pos.z+i}).name)
+		) then
+			return true
+		end
+	end
+	return false
+end
+
+--
+-- add_leaves_block(position, type of leaves, near trunk?)
+--
+-- Put a simple leaves block.
+-- Leaves must be positioned near a trunk or surrounded by air.
+-- Types of leaves are:
+-- 	0: dark leaves
+--	1: bright leaves (special)
+--
+function conifers:add_leaves_block(pos, special, near_trunk)
+	if (not conifers:are_leaves_surrounded(pos))
+	or near_trunk then
+		if special == 0 then
+			minetest.add_node(pos , { name = "conifers:leaves" })
+		else
+			minetest.add_node(pos , { name = "conifers:leaves_special" })
+		end
+	end
+end
+
+--
+-- make_leaves(middle point, min radius, max radius, type of leaves)
+--
+-- Make a circle of leaves with a center given by 'middle point'.
+-- Types of leaves are:
+-- 	0: dark leaves
+--	1: bright leaves (special)
+--
+function conifers:make_leaves(c, radius_min, radius_max, special)
+	--
+	-- Using the midpoint circle algorithm from Bresenham we can trace a circle of leaves.
+	--
+	for r = radius_min, radius_max do
+		local m_x = 0
+		local m_z = r
+		local m_m = 5 - 4 * r		
+		while m_x <= m_z do
+			if radius_max > 1 then
+				if r == 1 then
+					-- Add a square of leaves (fixing holes near the trunk).
+					-- [ ]   [ ]
+					--    [#]
+					-- [ ]   [ ]
+					conifers:add_leaves_block({x = -1 + c.x, 	y = c.y, z = 1 + c.z}, special)
+					conifers:add_leaves_block({x = 1 + c.x, 	y = c.y, z = 1 + c.z}, special)
+					conifers:add_leaves_block({x = -1 + c.x, 	y = c.y, z = -1 + c.z}, special)
+					conifers:add_leaves_block({x = 1 + c.x, 	y = c.y, z = -1 + c.z}, special)
+	 				--    [ ]
+					-- [ ][#][ ]
+					--    [ ]
+					conifers:add_leaves_block({x = c.x, 		y = c.y, z = -1 + c.z}, special, true)
+					conifers:add_leaves_block({x = c.x, 		y = c.y, z = 1 + c.z}, special, true)
+					conifers:add_leaves_block({x = -1 + c.x, 	y = c.y, z = c.z}, special, true)
+					conifers:add_leaves_block({x = 1 + c.x, 	y = c.y, z = c.z}, special, true)
+				else
+					conifers:add_leaves_block({x = m_x + c.x, 	y = c.y, z = m_z + c.z}, special)
+					conifers:add_leaves_block({x = m_z + c.x, 	y = c.y, z = m_x + c.z}, special)
+					conifers:add_leaves_block({x = -m_x + c.x, 	y = c.y, z = m_z + c.z}, special)
+					conifers:add_leaves_block({x = -m_z + c.x, 	y = c.y, z = m_x + c.z}, special)
+					conifers:add_leaves_block({x = m_x + c.x, 	y = c.y, z = -m_z + c.z}, special)
+					conifers:add_leaves_block({x = m_z + c.x, 	y = c.y, z = -m_x + c.z}, special)
+					conifers:add_leaves_block({x = -m_x + c.x, 	y = c.y, z = -m_z + c.z}, special)
+					conifers:add_leaves_block({x = -m_z + c.x, 	y = c.y, z = -m_x + c.z}, special)	
+				end
+			else
+				-- Put a small circle of leaves around the trunk.
+ 				--    [ ]
+				-- [ ][#][ ]
+				--    [ ]
+				conifers:add_leaves_block({x = c.x, 		y = c.y, z = -1 + c.z}, special, true)
+				conifers:add_leaves_block({x = c.x, 		y = c.y, z = 1 + c.z}, special, true)
+				conifers:add_leaves_block({x = -1 + c.x, 	y = c.y, z = c.z}, special, true)
+				conifers:add_leaves_block({x = 1 + c.x, 	y = c.y, z = c.z}, special, true)
+			end
+			-- Stuff...
+			if m_m > 0 then
+				m_z = m_z - 1
+				m_m = m_m - 8 * m_z
+			end
+			m_x = m_x + 1
+			m_m = m_m + 8 * m_x + 4
+		end
+	end
+end
+
+--
+-- make_conifer(position, type)
+--
+-- Make a conifer at a given position.
+-- Types are:
+-- 	0: regular pine
+--	1: narrow pine
+--
+function conifers:make_conifer(pos, conifer_type)
+	-- Check if we can gros a conifer at this place.
+	local node = minetest.get_node(pos).name
+	if minetest.get_node({x=pos.x, y=pos.y-1, z=pos.z}).name ~= "default:dirt_with_grass"
+	and (node ~= "air"
+		or node ~= "conifers:sapling"
+	) then
+		return false
+	--else
+		--if minetest.get_node({x = pos.x, y = pos.y, z = pos.z}).name == "conifers:sapling" then
+			--minetest.add_node(pos , {name = "air"})
+		--end
+	end
+	
+	local height = math.random(TRUNK_MINHEIGHT, TRUNK_MAXHEIGHT) -- Random height of the conifer.
+
+	-- Let's check if we can grow a tree here.
+	-- That means, we must have a column of 'height' high which contains
+	-- only air.
+	for j = 1, height - 1 do -- Start from 1 so we can grow a sapling.
+		if minetest.get_node({x=pos.x, y=pos.y+j, z=pos.z}).name ~= "air" then
+			-- Abort
+			return false
+		end
+	end
+
+	local t1 = os.clock()
+
+	local leaves_height = math.random(LEAVES_MINHEIGHT, LEAVES_MAXHEIGHT) -- Level from where the leaves grow.
+	local current_block = {} -- Duh...
+	local leaves_radius = 1
+	local leaves_max_radius = 2
+	local special = math.random(0, 1)
+
+	-- Create the trunk and add the leaves.
+	for i = 0, height - 1 do
+		current_block = {x=pos.x, y=pos.y+i, z=pos.z}
+		-- Put a trunk block.
+		minetest.add_node(current_block , {name = "conifers:trunk"})
+		-- Put some leaves.
+		if i >= leaves_height then
+			-- Put some leaves.
+			conifers:make_leaves({x=pos.x, y=pos.y+leaves_height+height-1-i, z=pos.z}, 1, leaves_radius, special)
+			--
+			-- TYPE OF CONIFER
+			--
+			if conifer_type == 1 then -- Regular type
+				-- Prepare the next circle of leaves.
+				leaves_radius = leaves_radius+1
+				-- Check if the current radius is the maximum radius at this level.
+				if leaves_radius > leaves_max_radius then
+					leaves_radius = 1
+					leaves_max_radius = leaves_max_radius+1
+					-- Does it exceeds the maximum radius?
+					if leaves_max_radius > LEAVES_MAXRADIUS then
+						leaves_max_radius = LEAVES_MAXRADIUS
+					end
+				end
+			else -- Narrow type
+				if i % 2 == 0 then
+					leaves_radius = LEAVES_NARROWRADIUS-math.random(0,1)
+				else
+					leaves_radius = math.floor(LEAVES_NARROWRADIUS/2)
+				end
+			end
+		end
+	end
+
+	-- Put a top leaves block.
+	current_block.y = current_block.y+1
+	conifers:add_leaves_block(current_block, special)
+
+	-- Blahblahblah
+	print (string.format('[conifers] A conifer has grown at ('..pos.x..','..pos.y..','..pos.z..') with a height of '..height..' after ca. %.2fs', os.clock() - t1))
+	return true
+end